How does nitro work. Installation of the nitro system. Can it be put on a regular engine
Probably everyone watched the films "Fast and the Furious" pumped cars, beautiful girls, desperate racers. After the success of this project, many racers in our country began to think about improving their cars. Of course, many have heard about “boosting”, but nitrous oxide on a car is something new. In the film, the racer presses the button and the car briefly "shoots" at breakneck speed! So what is it? And how does it work? Let's figure it out...
To be honest, this topic is shrouded in mystery, this film has spawned many different legends that are cultivated at an alarming rate in auto circles. Some believe that this mixture, when fed into the engine, "explodes", which gives the maximum push and the pistons begin to spin with force. Others believe that a few times the use of nitrous oxide and everything needs to be repaired the engine, because the valves, pistons and other elements simply burn out.
Are these myths true? And what is this mixture of gases for? Let's get into the details...
Let's start with the definition
Nitrous oxide (formula N2 O), also known as " NITRO" ( Nitrous Oxide System) It is a non-flammable, colorless gas with a slight pleasant odor and a sweetish taste. It is also used in medicine, where it is called "laughing gas", it has an intoxicating effect on a person. At high temperatures (about 500 degrees Celsius), 2N2O=2N2 + 2O decomposes, it is a very strong oxidizing agent, and therefore it perfectly supports combustion.
In cars, nitrous oxide is usually "packed" in special cylinders, where it is under pressure.
This mixture does not explode, and even more so does not burn through valves - pistons, this is a kind of fairly cheap way to short-term increase Engine efficiency and, accordingly, its power.
How nitrous oxide works
The supply of this gas is carried out directly with the fuel mixture into the combustion chambers. At the top point, when the piston compresses the mixture and the candle ignites it, the following happens:
1) Nitrous oxide, when exposed to high pressure and temperature, decomposes into nitrogen and oxygen.
2) Thus, it becomes possible to burn even more oxygen. And as you know, gasoline combines with oxygen to form a combustible composition.
3) So - there is 1.5 - 2 times more oxygen in N2O than in ordinary air. Thus, we burn much more working composition - which gives power to the engine.
4) Nitrogen also plays an important role, it improves the detonation properties and prevents the combustion process from developing instantly, that is, it simply does not allow it to explode. Another plus is the reduction in the temperature of the incoming air, which makes it denser, which improves its combustion in the engine cylinders.
I hope you understand! If you say in simple words, then it turns out nitrous oxide is a kind of combustion catalyst. Which, allows you to get more fuel and burn it better, this is how power is added. It is important to note that the settings must be very accurate, if incorrect, the engine can get a lean mixture, which will lead to its rapid overheating, because the speed is high here. And overheating is dangerous in itself.
System types
In tuning studios, they can offer you three different types of these systems, let's talk in more detail about each:
1) Dry - the easiest to install and use. It enters with the fuel-air mixture through the intake injectors. That is, the manifold remains "dry" from the fuel.
This can be achieved in two ways:
- Increased pressure from nitrous oxide devices, usually special cylinders. As a result, the total flow of the mixture is increased.
- Prolong the inclusion of fuel supply through the injectors by changing the firmware in the ECU. As a result, the injected amount of the “total” mixture increases.
Its “uncontrollability” is considered a big minus, that is, it is either turned on and working, or turned off and does not work.
2) wet type - here we can say that the nitrous supply is the same, but the fuel is supplied using an additional nozzle. This allows you to avoid overheating-detonations and get maximum efficiency. In such systems, additional “wet” fuel can be used, for which a special tank is made, it can be alcohols, gasolines, even gas with a higher octane number.
3) direct injection - the fuel is already ready-made composition enters the cylinders, where it burns completely. Moreover, mixing occurs before admission. Such a system is the most accurate and allows you to achieve the maximum power (which is possible), but it is the most expensive and the most difficult to install and configure.
Can it be put on a regular engine?
In principle it is possible, why not. However, you need to understand that "nitrous" is designed to increase power, which is achieved by high, sometimes very high speeds. That is, in simple words, this is the “red zone” of your motor. A conventional unit is not designed for this, so it will simply jam or break the connecting rods, turn the crankshaft liners, etc.
This system requires pumping your motor (the so-called), namely the replacement of all important elements. Starting from pistons, ending with a crankshaft, etc. As a rule, more durable options are installed, designed for high revs- this must be understood.
This additional tuning, already converted engine.
What can be harmful from nitrous oxide
Let's think about the harm from this system:
1) As we have already found out, this is a margin of safety. Conventional engines are unlikely to withstand its use, because it will drive it into the red zone, and here, as they say, there is a breakdown nearby.
2) It is imperative to improve the crank - connecting rod mechanism, the usual one may not withstand the load.
3) It is necessary to redo, as well as the exhaust gas outlet, often you have to sacrifice a catalyst.
4) In some cases, you have to tune the transmission. Other gears are installed, etc.
5) With some types of nitrous oxide, a flashing of the ECU is required.
6) Catalyst - if everything is set up correctly, it may not suffer, but as practice shows, when setting it up, it can still melt. So you need to be more careful.
TOTAL
As you can see, nitrous oxide does not explode, does not destroy, melts the engine inside. However, it is important to understand that it is not always advisable to put it on a standard motor. Because he just can not withstand the load!
in ampoules of 2 ml; in a plastic contour package (pallet) 5 pcs.; in a pack of cardboard 1 pack.
pharmachologic effect
pharmachologic effect- hypotensive, antianginal, vasodilating.Dosage and administration
I/V(strictly!)
The dosage regimen is set individually depending on the patient's condition and hemodynamic parameters. During the infusion, constant monitoring of SBP and diastolic blood pressure, heart rate, ECG, cardiac output, and (if possible) systolic and diastolic pressure in the pulmonary artery, wedge pressure in the pulmonary capillaries should be carried out.
Typically, an infusion solution containing 100 µg/ml nitroglycerin is used. This solution is prepared by diluting 5 ampoules of Nitro concentrate for infusion (corresponding to 50 mg of nitroglycerin) in 500 ml of 0.9% isotonic solution, 5% dextrose (glucose) solution or physiological glucose-salt solution to obtain a solution concentration of 0.1 mg / ml (should not be used in combination with other drugs). A more concentrated solution can be used, but it is not recommended to exceed a concentration of 400 µg/ml.
Glycerol trinitrate is adsorbed by plastic. Therefore, when mixing the infusion solution, glass vials should be used.
In / in the introduction begin slowly, at a rate of 10-20 mcg / min. The rate of administration can then be increased by 10-20 µg/min at 5-10 minute intervals depending on the response of the patient. A good therapeutic effect is usually achieved at an administration rate of 50-100 µg/min. Max speed administration is 400 mcg / min. The duration of drug administration depends on the dynamics of clinical symptoms and hemodynamic parameters and can range from several hours to 3 days. With prolonged administration of large doses, tolerance develops after 8-24 hours and an increase in dose may be required.
With the on / in the introduction of the drug Nitro, pronounced hemodynamic effects are observed. Therefore, the drug is used only in stationary conditions and requires constant monitoring of the function of the cardiovascular system. When using the drug, SBP should not decrease by more than 10-15 mm Hg. Art. - in patients with normal blood pressure; more than 5 mm Hg. Art. - in patients with arterial hypotension or prone to it, the heart rate should not increase by more than 5 bpm, if at the same time the clinical picture is clearly improving.
Due to the fact that the withdrawal syndrome (the “rebound” phenomenon) is not excluded, it is not recommended to abruptly stop the administration of the drug, the dose should be reduced slowly.
Terms of dispensing from pharmacies
On prescription.
Storage conditions for Nitro
At a temperature of 15-25 °C.Keep out of the reach of children.
Expiry date of Nitro
3 years.Do not use after the expiry date stated on the packaging.
Synonyms of nosological groups
| Category ICD-10 | Synonyms of diseases according to ICD-10 |
|---|---|
| I10 Essential (primary) hypertension | arterial hypertension |
| Arterial hypertension | |
| arterial hypertension | |
| Sudden increase in blood pressure | |
| Hypertensive state | |
| Hypertensive crises | |
| hypertension | |
| Arterial hypertension | |
| Hypertension, malignant | |
| Essential hypertension | |
| Hypertonic disease | |
| Hypertensive crises | |
| Hypertensive crisis | |
| Hypertension | |
| malignant hypertension | |
| Malignant hypertension | |
| Isolated systolic hypertension | |
| Hypertensive crisis | |
| Primary arterial hypertension | |
| Essential arterial hypertension | |
| Essential arterial hypertension | |
| Essential hypertension | |
| Essential hypertension | |
| I15 Secondary hypertension | arterial hypertension |
| Arterial hypertension | |
| Arterial hypertension of the crisis course | |
| Arterial hypertension complicated by diabetes mellitus | |
| arterial hypertension | |
| Vasorenal hypertension | |
| Sudden increase in blood pressure | |
| Hypertensive circulatory disorders | |
| Hypertensive state | |
| Hypertensive crises | |
| hypertension | |
| Arterial hypertension | |
| Hypertension, malignant | |
| Symptomatic hypertension | |
| Hypertensive crises | |
| Hypertensive crisis | |
| Hypertension | |
| malignant hypertension | |
| Malignant hypertension | |
| Hypertensive crisis | |
| Exacerbation of hypertension | |
| Renal hypertension | |
| Renovascular hypertension | |
| Renovascular hypertension | |
| Symptomatic arterial hypertension | |
| Transient arterial hypertension | |
| I20.0 Unstable angina | Heberden's disease |
| Unstable angina | |
| Unstable angina | |
| I21 Acute myocardial infarction | left ventricular infarction |
| Myocardial infarction without Q wave | |
| Myocardial infarction in the acute period | |
| Myocardial infarction non-transmural (subendocardial) | |
| acute myocardial infarction | |
| Myocardial infarction with and without pathological Q wave | |
| Myocardial infarction transmural | |
| Myocardial infarction complicated by cardiogenic shock | |
| Non-transmural myocardial infarction | |
| Acute phase of myocardial infarction | |
| Acute myocardial infarction | |
| Subacute stage of myocardial infarction | |
| Subacute period of myocardial infarction | |
| subendocardial myocardial infarction | |
| Thrombosis of the coronary artery(s) | |
| Threatening myocardial infarction | |
| R07.2 Pain in the region of the heart | Pain syndrome in myocardial infarction |
| Pain in cardiac patients | |
| Cardialgia | |
| Cardialgia on the background of dyshormonal myocardial dystrophy | |
| Cardiac syndrome | |
| Cardioneurosis | |
| Myocardial ischemic pain | |
| Neuroses of the heart | |
| Pericardial pain | |
| Pseudoangina pectoris | |
| Functional cardialgia | |
| Z100* CLASS XXII Surgical practice | Abdominal surgery |
| Adenomectomy | |
| Amputation | |
| Angioplasty of coronary arteries | |
| Angioplasty of the carotid arteries | |
| Antiseptic skin treatment for wounds | |
| Antiseptic hand treatment | |
| Appendectomy | |
| Atherectomy | |
| Balloon coronary angioplasty | |
| Vaginal hysterectomy | |
| Crown bypass | |
| Interventions on the vagina and cervix | |
| Bladder interventions | |
| Intervention in the oral cavity | |
| Restorative and reconstructive operations | |
| Hand hygiene of medical personnel | |
| Gynecological surgery | |
| Gynecological interventions | |
| Gynecological operations | |
| Hypovolemic shock during surgery | |
| Disinfection of purulent wounds | |
| Disinfection of wound edges | |
| Diagnostic interventions | |
| Diagnostic procedures | |
| Diathermocoagulation of the cervix | |
| Long-term surgery | |
| Replacement of fistula catheters | |
| Infection during orthopedic surgery | |
| Artificial heart valve | |
| cystectomy | |
| Brief outpatient surgery | |
| Short-term operations | |
| Short term surgical procedures | |
| Cricothyrotomy | |
| Blood loss during surgery | |
| Bleeding during surgery and in the postoperative period | |
| Culdocentesis | |
| Laser coagulation | |
| Laser coagulation | |
| Laser coagulation of the retina | |
| Laparoscopy | |
| Laparoscopy in gynecology | |
| CSF fistula | |
| Minor gynecological surgeries | |
| Minor surgical interventions | |
| Mastectomy and subsequent plasty | |
| Mediastinotomy | |
| Microsurgical operations on the ear | |
| Mucogingival operations | |
| Suturing | |
| Minor surgical interventions | |
| Neurosurgical operation | |
| Immobilization of the eyeball in ophthalmic surgery | |
| Orchiectomy | |
| Complications after tooth extraction | |
| Pancreatectomy | |
| Pericardectomy | |
| The period of rehabilitation after surgical operations | |
| The period of convalescence after surgical interventions | |
| Percutaneous transluminal coronary angioplasty | |
| Pleural thoracocentesis | |
| Pneumonia postoperative and post-traumatic | |
| Preparation for surgical procedures | |
| Preparing for surgery | |
| Preparation of the surgeon's hands before surgery | |
| Preparing the colon for surgery | |
| Postoperative aspiration pneumonia in neurosurgical and thoracic operations | |
| Postoperative nausea | |
| Postoperative bleeding | |
| Postoperative granuloma | |
| Postoperative shock | |
| Early postoperative period | |
| Myocardial revascularization | |
| Resection of the apex of the tooth root | |
| Resection of the stomach | |
| Bowel resection | |
| Uterine resection | |
| Liver resection | |
| Resection of the small intestine | |
| Resection of a part of the stomach | |
| Reocclusion of the operated vessel | |
| Bonding tissue during surgery | |
| Removal of stitches | |
| Condition after eye surgery | |
| Condition after surgery | |
| Condition after surgical interventions in the nasal cavity | |
| Condition after resection of the stomach | |
| Condition after resection of the small intestine | |
| Condition after tonsillectomy | |
| Condition after removal of the duodenum | |
| Condition after phlebectomy | |
| Vascular surgery | |
| Splenectomy | |
| Sterilization of the surgical instrument | |
| Sterilization of surgical instruments | |
| Sternotomy | |
| Dental operations | |
| Dental intervention on periodontal tissues | |
| Strumectomy | |
| Tonsillectomy | |
| Thoracic Surgery | |
| Thoracic operations | |
| Total gastrectomy | |
| Transdermal intravascular coronary angioplasty | |
| Transurethral resection | |
| Turbinectomy | |
| Removal of a tooth | |
| Cataract removal | |
| Removal of cysts | |
| Tonsil removal | |
| Removal of fibroids | |
| Removal of mobile milk teeth | |
| Removal of polyps | |
| Removal of a broken tooth | |
| Removal of the body of the uterus | |
| Suture removal | |
| Urethrotomy | |
| CSF fistula | |
| Frontoethmoidogaimorotomy | |
| Surgical infection | |
| Surgical treatment of chronic leg ulcers | |
| Surgery | |
| Surgery in the anus | |
| Surgical operation on the large intestine | |
| Surgical practice | |
| surgical procedure | |
| Surgical interventions | |
| Surgical interventions on the gastrointestinal tract | |
| Surgical interventions on the urinary tract | |
| Surgical interventions on the urinary system | |
| Surgical interventions on the genitourinary system | |
| Surgical interventions on the heart | |
| Surgical manipulations | |
| Surgical operations | |
| Surgical operations on the veins | |
| Surgical intervention | |
| Surgical intervention on the vessels | |
| Surgical treatment of thrombosis | |
| Surgery | |
| Cholecystectomy | |
| Partial resection of the stomach | |
| Transperitoneal hysterectomy | |
| Percutaneous transluminal coronary angioplasty | |
| Percutaneous transluminal angioplasty | |
| Bypass coronary arteries | |
| Tooth extirpation | |
| Extraction of milk teeth | |
| Pulp extirpation | |
| extracorporeal circulation | |
| Tooth extraction | |
| Extraction of teeth | |
| Cataract Extraction | |
| Electrocoagulation | |
| Endourological interventions | |
| Episiotomy | |
| Ethmoidectomy |
This is not news to anyone. But why, the use of this system is capable of so instantly increase car speed? A special topic is popular with fans of tuning vases with their own hands. The answer lies in the essence of the operation of the engine itself. Why is the car moving? Because the fuel-air mixture burns in the cylinders, setting the pistons in motion. The pistons, in turn, transmit this rotational movement to the wheels. Now let's think logically. How to increase the amount of rotational movement, or as they say, torque? It is necessary to increase the amount of fuel burned per unit of time. It seems to be understandable, but in order to burn more fuel, more oxygen is required. That's why we need nitrous oxide.
How Nitro Works
Instant increase in speed comes from an increase in power. To increase power without putting much effort in a significant alteration of the engine, it is enough to take just three simple (or not so) steps.First, as mentioned earlier, in order for the fuel to burn, oxygen is needed. Nitrous oxide (N2O) is essentially oxygen. Nitros is not the energy that drives the car forward, the energy is the fuel, and the nitrous oxide just helps burn more of it. More fuel burns in the cylinder per unit of time - more force with which the piston is pushed out, and hence more power. Everything is pretty simple here.
Fuel structure
Second power step(or as we have already figured out the combustibility of fuel), this is the structure of the fuel. Or rather, even to say its state of aggregation. After all, gasoline (or any other fuel) will not burn in a closed space, which is the combustion chamber, in a liquid state. It will be more precise, but this one will not be exactly what we need. To achieve maximum efficiency, it is necessary that the fuel be in a vapor state. Therefore, the better the valve that sprays the fuel (in the injectors), the faster it will burn out. Ideally, the size of a gasoline droplet in the atomized state should be ten times smaller than the size of an ordinary droplet.The composition of nitrous oxide, the result
The last step to increasing power lies in the quality of the air. Normal air we breathe is 78% nitrogen, 21% oxygen and 1% other gases. Nitrous oxide contains 67% nitrogen and 33% oxygen. More oxygen per unit volume of nitro allows more fuel to be burned. It is a fact. But we must remember that cylinder volume is also not infinite, and therefore the amount of fuel-air mixture that can fit in the combustion chamber also has its limit. How to increase this limit without changing the design of the cylinders? There is no secret here, because this is simple thermodynamics, studied at school. As the temperature decreases, all bodies shrink. And fuel is no exception. That is, if lower the temperature of the air-fuel mixture, then you can increase the concentration of this mixture per unit volume. Nitrous oxide will also help with this. Nitro is supplied as liquefied gas, and the evaporation temperature of any liquefied gas is several times lower than the ambient temperature. Here is the answer. By using nitrous oxide instead of ordinary air, we kill two birds with one stone. First, we increase the amount of oxygen, which means we increase the amount of fuel burned. Secondly, the volume of the combustible mixture increases by lowering the temperature, which also increases power. Engine tuning and tuning with your own hands - easy!So, using nitros on your car, even without a cardinal alteration of the engine, you can very quickly increase power, and as a result, speed. One has only to remember that the use of nitro makes your engine run at the maximum allowable frequency, which means that all parts will wear out faster, and the life of the motor is significantly reduced. Do-it-yourself tuning is easy, good luck to you!
The nitro group has a structure intermediate between the two limiting resonance structures:
The group is planar; the N and O atoms have sp 2 hybridization, N-O bonds equivalent and almost one and a half; bond lengths, eg. for CH 3 NO 2, 0.122 nm (N-O), 0.147 nm (C-N), ONO angle 127°. The C-NO 2 system is flat with a low barrier of rotation around C-N bonds.
H Itro compounds having at least one a-H-atom can exist in two tautomeric forms with a common mesomeric anion. O-shape aci-nitro compound or nitrone to-that:
Known diff. derivatives of nitronic acids: salts of the f-ly RR "C \u003d N (O) O - M + (salts of nitro compounds), ethers (nitronic esters), etc. Ethers of nitronic acids exist in the form of iis- and trans- isomers There are cyclic ethers, for example N-oxides of isoxazolines.
Name nitro compounds are produced by adding the prefix "nitro" to the name. base connections, if necessary adding a digital indicator, e.g. 2-nitropropane. Name salts of nitro compounds are produced from the names. either C-form, or aci-form, or nitrone to-you.
physical properties. The simplest nitroalkanes are colorless. liquids. Phys. Holy Islands of certain aliphatic nitro compounds are given in the table. Aromatic nitro compounds-bestsv. or light yellow, high-boiling liquids or low-melting solids, with a characteristic odor, poorly sol. in water tends to be distilled with steam.
PHYSICAL PROPERTIES OF SOME ALIPHATIC NITRO COMPOUNDS
* At 25°C. ** At 24°C. *** At 14°C.
In the UV spectra of aliphatic nitro compounds l max 200-210 nm (intense band) and 270-280 nm (weak band); for salts and esters of nitrone to-t resp. 220-230 and 310-320 nm; for gem-dinitrocomponent. 320-380 nm; for aromatic nitro compounds, 250–300 nm (the intensity of the band sharply decreases when the coplanarity is violated).
In the PMR spectrum, chem. shifts of a-H-atom depending on the structure 4-6 ppm In the NMR spectrum 14 N and 15 N chem. shift 5 from - 50 to + 20 ppm
In the mass spectra of aliphatic nitro compounds (with the exception of CH 3 NO 2), the peak mol. ion is absent or very small; main fragmentation process - elimination of NO 2 or two oxygen atoms to form a fragment equivalent to nitrile. Aromatic nitro compounds are characterized by the presence of a peak mol. and she ; main the peak in the spectrum corresponds to the ion produced by elimination of NO 2 .
Chemical properties. The nitro group is one of the most strong electron-withdrawing groups and is able to effectively delocalize negative. charge. In the aromatic conn. as a result of induction and especially mesomeric effects, it affects the electron density distribution: the nucleus acquires a partial positive. charge, to-ry localized Ch. arr. in ortho and para positions; Hammett constants for the NO 2 group s m 0.71, s n 0.778, s + n 0.740, s - n 1.25. So arr., the introduction of the NO 2 group dramatically increases the reaction. ability org. conn. in relation to the nucleoph. reagents and makes it difficult to R-tion with elektrof. reagents. This determines the widespread use of nitro compounds in org. synthesis: the NO 2 group is introduced into the desired position of the org molecule. Comm., carry out decomp. p-tion associated, as a rule, with a change in the carbon skeleton, and then transformed into another function or removed. In the aromatic In a row, a shorter scheme is often used: nitration-transformation of the NO 2 group.
Mn. transformations of aliphatic nitro compounds take place with a preliminary. isomerization to nitrone to-you or the formation of the corresponding anion. In solutions, the balance is usually almost completely shifted towards the C-form; at 20 °С, the proportion of the aci-form for nitromethane is 1 10 -7, for nitropropane 3. 10 -3 . Nitronovye to-you in svob. the form is usually unstable; they are obtained by careful acidification of salts of nitro compounds. Unlike nitro compounds, they conduct current in solutions and give a red color with FeCl 3 . Aci-nitro compounds are stronger CH-acids (pK a ~ 3-5) than the corresponding nitro compounds (pK a ~ 8-10); the acidity of nitro compounds increases with the introduction of electron-withdrawing substituents in the a-position to the NO 2 group.
The formation of nitrone to-t in a series of aromatic nitro compounds is associated with the isomerization of the benzene ring into the quinoid form; for example, nitrobenzene forms with conc. H 2 SO 4 colored salt product f-ly I, o-nitrotoluene exhibits photochromism as a result vnutrimol. proton transfer to form a bright blue O-derivative:
Under the action of bases on primary and secondary nitro compounds, salts of nitro compounds are formed; ambident anions of salts in p-tions with electrophiles are able to give both O- and C-derivatives. So, during the alkylation of salts of nitro compounds with alkyl halides, trialkylchlorosilanes or R 3 O + BF - 4, O-alkylation products are formed. Recent m.b. also obtained by the action of diazomethane or N,O-bis-(trimethylsilyl)acetamide on nitroalkanes with pK a< 3 или нитроновые к-ты, напр.:
Acyclic alkyl esters of nitrone to-t are thermally unstable and decompose according to intramol. mechanism:
; this
p-tion can be used to obtain carbonyl compounds. Silyl ethers are more stable. See below for the formation of C-alkylation products.
For nitro compounds, p-tions with a break in the C-N bond, along the bonds N \u003d O, O \u003d N O, C \u003d N -\u003e O and p-tions with the conservation of the NO 2 group are characteristic.
R-ts and and with r and ry v o m s vyaz z and C-N. Primary and secondary nitro compounds at loading. with a miner. to-tami in the presence. alcohol or aqueous solution of alkali form carbonyl Comm. (see Neph reaction). R-tion passes through the interval. the formation of nitrone to-t:
As a source Comm. silyl nitrone ethers can be used. Action strong to-t on aliphatic nitro compounds can lead to hydroxamic acids, for example:
The method is used in the industry for the synthesis of CH 3 COOH and hydroxylamine from nitroethane. Aromatic nitro compounds are inert to the action of strong to-t.
Under the action of reducing agents (eg, TiCl 3 -H 2 O, VCl 2 -H 2 O-DMF) on nitro compounds or oxidizing agents (KMnO 4 -MgSO 4, O 3) on salts of nitro compounds, ketones and aldehydes are formed.
Aliphatic nitro compounds containing a mobile H atom in the b-position to the NO 2 group, under the action of bases, easily eliminate it in the form of HNO 2 with the formation of olefins. Thermal flows in the same way. decomposition of nitroalkanes at temperatures above 450 °. Vicinal dinitrocomponents. when treated with Ca amalgam in hexamstanol, both NO 2 groups are cleaved off, Ag-salts of unsaturated nitro compounds can dimerize upon loss of NO 2 groups:
Nucleof. substitution of the NO 2 group is not typical for nitroalkanes, however, when thiolate ions act on tertiary nitroalkanes in aprotic p-solvents, the NO 2 group is replaced by a hydrogen atom. P-tion proceeds by an anion-radical mechanism. In the aliphatic and heterocyclic. conn.the NO 2 group with a multiple bond is relatively easily replaced by a nucleophile, for example:
In the aromatic conn. nucleoph. the substitution of the NO 2 group depends on its position with respect to other substituents: the NO 2 group, which is in the meta position with respect to the electron-withdrawing substituents and in the ortho and para positions to the electron donor, has a low reaction. ability; reaction the ability of the NO 2 group, located in the ortho- and para-positions to electron-withdrawing substituents, increases markedly. In some cases, the substituent enters the ortho position to the leaving NO 2 group (for example, when aromatic nitro compounds are loaded with an alcohol solution of KCN, Richter's solution):
R-ts and and about with I z and N \u003d O. One of the most important p-tsy-restoration, leading in the general case to a set of products:
Azoxy-(II), azo-(III) and hydrazo compounds. (IV) are formed in an alkaline environment as a result of the condensation of intermediate nitroso compounds. with amines and hydroxylamines. Carrying out the process in an acidic environment excludes the formation of these substances. Nitroso-compound. recover faster than the corresponding nitro compounds, and select them from the reaction. mixtures usually fail. Aliphatic nitro compounds are reduced to azoxy or azo compounds by the action of Na alcoholates, aromatic ones by the action of NaBH 4, the treatment of the latter with LiAlH 4 leads to azo compounds. Electrochem. the reduction of aromatic nitro compounds under certain conditions allows you to get any of the presented derivatives (with the exception of nitroso compounds); it is convenient to obtain hydroxylamines from mononitroalkanes and amidoximes from gem-dinitroalkane salts by the same method:
Many methods are known for the reduction of nitro compounds to amines. Widely used iron filings, Sn and Zn in the presence. to-t; with catalytic hydrogenation as catalysts use Ni-Raney, Pd / C or Pd / PbCO 3, etc. Aliphatic nitro compounds are easily reduced to amines LiAlH 4 and NaBH 4 in the presence. Pd, Na and Al amalgams, when heated. with hydrazine over Pd/C; for aromatic nitro compounds, TlCl 3, CrCl 2 and SnCl 2 are sometimes used, aromatic. polynitro compounds are selectively reduced to nitramines with Na hydrosulfide in CH 3 OH. There are ways to choose. recovery of the NO 2 group in polyfunctional nitro compounds without affecting other f-tions.
Under the action of P(III) on aromatic nitro compounds, a succession occurs. deoxygenation of the NO 2 group with the formation of highly reactive nitrenes. R-tion is used for the synthesis of condenser. heterocycles, for example:
Under the same conditions, silyl esters of nitrone acids are transformed into silyl derivatives of oximes. Treatment of primary nitroalkanes with PCl 3 in pyridine or NaBH 2 S leads to nitriles. Aromatic nitro compounds containing a double bond substituent or a cyclopropyl substituent in the ortho position rearrange in an acidic medium into o-nitrosoketones, for example:
H itro compounds and nitrone ethers react with an excess of Grignard's reagent to give hydroxylamine derivatives:
R-tions for bonds O \u003d N O and C \u003d N O. Nitro compounds enter into p-tions of 1,3-dipolar cycloaddition, for example:
Naib. this p-tion easily flows between nitrone esters and olefins or acetylenes. In cycloaddition products (mono- and bicyclic dialkoxyamines) under the action of nucleoph. and elektrof. N - O bond reagents are easily cleaved, which leads to decomp. aliphatic and hetero-cyclic. conn.:
For preparative purposes, stable silyl nitrone esters are used in the district.
R-ts and with the preservation of the NO 2 group. Aliphatic nitro compounds containing an a-H-atom are easily alkylated and acylated to form, as a rule, O-derivatives. However, mutually mod. dilithium salts of primary nitro compounds with alkyl halides, anhydrides or acid halides carbon kit leads to products of C-alkylation or C-acylation, for example:
Known examples vnutrimol. C-alkylations, e.g.:
Primary and secondary nitro compounds react with aliphatic. amines and CH 2 O with the formation of p-amino derivatives (p-tion Mannich); in the district, you can use pre-obtained methylol derivatives of nitro compounds or amino compounds:
The activating effect of the NO 2 group on the nucleoph. substitution (especially in the ortho position) is widely used in org. synthesis and industry. P-tion proceeds according to the scheme of accession-cleavage from the intermediate. the formation of an s-complex (Meisenheimer complex). According to this scheme, halogen atoms are easily replaced by nucleophiles:
Known examples of substitution by the anion-radical mechanism with electron capture aromatic. connection and emission of a halide ion or other groups, for example. alkoxy, amino, sulfate, NO - 2. In the latter case, the district passes the easier, the greater the deviation of the NO 2 group from coplanarity, for example: in 2,3-dinitrotoluene it is replaced in the main. the NO 2 group in position 2. The H atom in aromatic nitro compounds is also capable of nucleophage. substitution-nitrobenzene at heating. with NaOH forms o-nitrophenol.
The nitro group facilitates aromatic rearrangements. conn. according to the intramol mechanism. nucleoph. substitution or through the stage of formation of carbanions (see Smiles rearrangement).
The introduction of the second NO 2 group accelerates the nucleophane. substitution. H introconnections in the presence. bases are added to aldehydes and ketones, giving nitroalcohols (see Henri reactions), primary and secondary nitro compounds, to Comm., containing activir. double bond (Michael region), for example:
Primary nitro compounds can enter into the Michael p-tion with the second molecule of the unsaturated compound; this p-tion with the last. trancethe formation of the NO 2 group is used for the synthesis of poly-function. aliphatic connections. The combination of Henri and Michael p-tions leads to 1,3-dinitro compounds, for example:
To inactivated only Hg-derivatives of gem-di- or trinitro compounds, as well as IC (NO 2) 3 and C (NO 2) 4, are added to the double bond, while products of C- or O-alkylation are formed; the latter can enter into a cyclo-addition p-tion with the second olefin molecule:
Easily enter into p-tion accession nitroolefins: with water in a slightly acidic or slightly alkaline medium with the latter. Henri retroreaction they form carbonyl Comm. and nitroalkanes; with nitro compounds containing a-H-atom, poly-nitro compounds; add and other CH-acids, such as acetylacetone, esters of acetoacetic and malonic acid, Grignard reagents, as well as nucleophiles such as OR -, NR - 2, etc., for example:
Nitroolefins can act as dienophiles or dipolarophiles in p-tions of diene synthesis and cycloaddition, and 1,4-dinitrodienes can act as diene components, for example:
Receipt. In the industry, lower nitroalkanes are obtained by liquid-phase (Konovalov's district) or vapor-phase (Hess method) nitration of a mixture of ethane, propane and butane, isolated from natural gas or obtained by oil refining (see Nitration). Higher nitro compounds are also obtained in this way, for example. nitrocyclohexane is an intermediate in the production of caprolactam.
In the laboratory, nitration of nitric acid is used to obtain nitroalkanes. with activated a methylene group; a convenient method for the synthesis of primary nitroalkanes is the nitration of 1,3-indanedione with the last. alkaline hydrolysis of a-nitroketone:
Aliphatic nitro compounds also receive interaction. AgNO 2 with alkyl halides or NaNO 2 with esters of a-halocarboxylic-new to-t (see Meyer reaction). Aliphatic nitro compounds are formed from the oxidation of amines and oximes; oxidation of oximes - a method for obtaining gem-di- and gem-trinitro compounds, for example: