CN1600778A

CN1600778A - Preparation of triazo alkane

Info

Publication number: CN1600778A
Application number: CN 03157575
Authority: CN
Inventors: 张晟源; 唐光诗
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2003-09-25
Filing date: 2003-09-25
Publication date: 2005-03-30

Abstract

A process for preparing triazine alkenes by formaldehyde and acetaldehyde includes aldol condensation, esterifing, nitrating to prepare 2-methyl-2-nitrine methyl-1,3-biazine propane.

Description

Preparation of triazoalkanes

The invention relates to the technical field of preparation methods of 2-azidomethyl-1, 3-diazidopropane and 2-methyl-2-azidomethyl-1, 3-diazidopropane. The compound has the characteristics of good stability, high heat of formation, large heat of combustion, fast combustion speed and the like, and has high application value in the aspects of plasticizers of gas generating agents and solid propellants.

Background artthe synthesis and research of azide have been over a hundred years of history, and chemists have conducted a great deal of research on the aspects of structure, performance, application and the like of azide, and have synthesized azide with a great deal of application value. Since the seventies, extensive and intensive research on the application of azido organic compounds as energetic materials has been carried out abroad, particularly in the United states, and the results show that the use of azido-containing binders, plasticizers, oxidizers and other additives in energetic materials such as propellant, propellant and high explosive not only increases the energy level (each azido group provides 356kJ/mol of enthalpy of formation) but also imparts many other excellent properties: the nitrogen content of the system is improved without influencing the carbon-hydrogen ratio of the system, and the exhaust amount of the system during combustion is increased; increasing the combustion rate of propellant charge or propellant without increasing the flame temperature; the target features produced by various propulsion systems are reduced, thereby improving the stealth of the weapon. Therefore, the synthesis and application studies of azide-based compounds such as adhesives, plasticizers and other additives, which are currently performed in the field of energetic materials, are considered as one of the research focuses in this field.

Currently synthesized azide compounds are generally classified into azidopolyethers, azidonitroamines, azidonitro compounds, azidofluorodinitro compounds, and azidoalkanes, azidoethers, and azidoesters. Most of the azido-alkane compounds are compatible with HMX and RDX, have excellent plasticizing performance, can replace inert plasticizers in the formula of the solid propellant, and have wide practical value. Azide derivatives of pentaerythritol, for example, have good thermal stability, high heat of formation, large heat of combustion and high number of combustionsIt can be used as plasticizer of gas generating agent and solid propellant. At present, the synthesized triazanes mainly contain NO₂C(CH₂N₃)₃、CH₃CH₂C(CH₂N₃)₃And the like. For 2-azidomethyl-1, 3-diazidopropane, no report on the compound and the synthesis thereof is seen at present. 2-methyl-2-azidomethyl-1, 3-diazidopropane has been reported in a small amount abroad, but basically, the subsequent reaction is carried out by using the compound, but only one article mentions the synthesis method, and the article adopts trimethylolethane (PG) as a starting material, and the alcohol is not sold at home and has high cost; meanwhile, the preparation process requires reaction under the conditions of no oxygen, no water and high temperature, so that the method is not practical, therefore, cheap and easily-obtained formaldehyde and acetaldehyde are used as initial raw materials, a synthetic route is simplified, and the 2-methyl-2-azidomethyl-1, 3-diazidopropane is prepared by adopting a simple and feasible synthetic route.

The present invention relates to the preparation of two triazanes, which are prepared analogously and can be extended to the preparation of such compounds. The method is characterized in that formaldehyde and acetaldehyde are used as raw materials, and a pure product of 2-methyl-triazo methyl propane is prepared by the simplest and most convenient and economical method through three reactions, recrystallization, column layer separation and other technologies; nitromethane is used as a raw material, and the triazo methyl methane is prepared for the first time through steps of aldol condensation, esterification, reduction, azidation and the like, and the triazo alkanes are preliminarily determined to have excellent plasticizing performance and are expected to have important application values in the aspects of energetic material additives and organic synthesis.

The method is improved in the aspect of preparing the trimethylolethane, does not adopt ion exchange resin, is simpler in separation method, is more economical and practical, and is easy for industrial production. The selected alkali metals mainly comprise sodium hydroxide, potassium hydroxide, calcium hydroxide and the like, and the sodium hydroxide is most suitable, so that the yield is highest. The method for synthesizing the azide mainly comprises the following steps: preparing from halide; from alcohols and epoxy compounds; prepared from compounds containing azido groups; from nitrogen-containing compounds, and the like. The process used in the present invention belongs to the processes for obtaining alcohols and oxygen-containing compounds, which are also used in the literature, but they are prepared and separated under high temperature and absolutely anhydrous conditions in the synthesis of azides, resulting in increased difficulty of synthesis. The invention finds the most economic and mild reaction route through repeated experiments, and aims to apply the product to energetic additives and precursors of organic reactions. Alkali metal azides that can be used are lithium azide, potassium azide and sodium azide, with sodium azide being preferred. And separating the product by silica gel column chromatography to obtain the azide product.

In the aspect of preparing 2-azidomethyl-1, 3-diazidopropane, nitromethane is used as an initial raw material to carry out reaction to prepare a target product, and H is used for replacing CH₃C(CH₂N₃)₃The methyl in the (A) has smaller steric hindrance and improved symmetry, and other properties are changed along with the methyl, so that the (A) is expected to have greater application value in energetic additives and organic synthesis. In the preparation process, the most critical step is the reduction of the nitro group to hydrogen, while the other steps are analogous to the synthesis of 2-methyl-2-azidomethyl-1, 3-diazidopropane. In the existing method for reducing nitro, tri-n-butyltin hydride is mostly used for reduction abroad, but the compound is not produced at home at present and cannot be purchased through import for a while, so that the self-made CH is adopted₃S^-Na⁺Reducing to prepare the 2-azidomethyl-1, 3-diazidopropane. CH (CH)₃S^-Na⁺The reduction mechanism is as follows:

example 1:

preparation and characterization of 1-trimethylolethane

74ml of 36% formaldehyde was mixed well with 200ml of water in a three-necked flask. 21ml of 98% propanal was slowly added dropwise to the mixture, 28.8g of 50% NaOH solution was added over 30min, and the reaction was maintained for 3h with cooling with water to keep the temperature below 30 ℃.

After the reaction is finished, the pH value is neutralized to 8 by formic acid, the solution is clear, and acid is continuously added until the solution is neutral. Heating the solution, concentrating under reduced pressure, removing the generated sodium formate precipitate by filtration, washing with inorganic acid and water for several times, removing other unreacted impurities to obtain colorless clear solution, distilling under reduced pressure to remove the solvent to obtain a solid crude product, and recrystallizing with methanol to obtain white needle-like crystals, 26.23g, and the yield of 78%.

The product analysis data is as follows:

IR：3322cm^-1is O-H stretching vibration, 2942cm^-1Is the stretching vibration of C-H,

1397cm^-1is deformation vibration of O-H, 1025cm^-1C-O stretching vibration.

¹H NMR(CH₃OD)：δ4.9646(s，3H，OH)3.6720(s，6H，CH₂)1.0381(s，3H，CH₃)

Melting point: 199.5 ℃ C, in accordance with literature values.

Preparation and characterization of 22-methyl-2-p-toluenesulfonic acid methyl-1, 3-di-p-toluenesulfonic acid propylene glycol

11.6g of p-toluenesulfonyl chloride was dissolved in 20ml of pyridine, cooled to below-5 ℃, then slowly added dropwise to 5ml of pyridine solution containing 2g of trimethylolethane, reacted at-5 ℃ for 10 hours, then reacted at room temperature for 10 hours, poured into water to obtain a yellow solid, 9.15g, washed several times with ethanol and water, and then recrystallized from toluene to obtain white crystals, 9.05g, m.p. 104 ℃, yield 93%.

The product analysis data is as follows:

IR：2964cm^-1C-H stretching vibration; 1600cm^-1、1458cm^-1Is a characteristic peak of a benzene ring;

¹H NMR(CD₃COCD₃): delta 7.8300(q, 12H, four hydrogens of p-substituted benzene) 3.8773(s, 6H, CH)₂)2.4473(s, 9H, CH on the benzene ring)₃)0.8968(s，3H，CH₃)3.1764 is the impurity peak of acetone solvent.

Melting point: 104 deg.C

Preparation and characterization of 32-methyl-2-azidomethyl-1, 3-diazidopropane

3g of 2-methyl-2-p-toluenesulfonate methyl-1, 3-di-p-toluenesulfonate propylene glycol was dissolved in 20ml of DMF, and after heating to 60 ℃ and stirring, 1.2g of NaN dissolved therein was slowly dropped₃And 3ml of deionized water solution is reacted at 80 ℃ for 72 hours, the TLC tracking reaction is carried out, after the raw material points completely disappear and the concentration of each product point is basically unchanged, the reaction solution is poured into water, cooled, oily liquid drops are collected, the mixture is washed for a plurality of times by distilled water, absolute ethyl ether is extracted, an extract liquid is collected, and yellow oily liquid is obtained after the solvent is distilled off. Column chromatography (ethyl acetate/petroleum ether) was performed on a silica gel column to obtain 0.4537g of a yellow liquid, which was the product in 45.3% yield. The product analysis data is as follows:

IR：2977cm^-1、2930cm^-1、2850cm^-1is treated by C-H stretching vibration, 2100cm^-1、1293cm^-1All are characteristic peaks of azide groups.

¹H NMR(CDCl₃)：δ3.2020(s，6H，CH₂)0.9219(s，3H，CH₃) The element composition (mass fraction): according to C₅H₉N₉Calculated values: c54.05, H8.11, N37.83, found: c54.89, H7.78, N37.33

Example 2:

preparation of 12-nitro-2-hydroxymethyl-1, 3-propanediol

3.56ml of nitromethane are added dropwise to a suspension of 5.96g of paraformaldehyde and 3g of KOH in 30ml of ethyl acetate, the temperature is controlled at about 35 ℃, the mixture is stirred for several hours, the mixture is heated in a water bath to a yellow transparent liquid, the yellow transparent liquid is cooled to obtain a yellow solid, and the ethyl acetate is recrystallized to obtain 8.6g of yellow crystals with the yield of 87%.

The product analysis data is as follows:

IR：3416cm^-1O-H stretching vibration of alcohol, 2933cm^-1C-H stretching vibration, 1543cm^-1，1344cm^-1Is NO₂Characteristic peak of 1062cm^-1C-O stretching vibration.

¹H NMR(CDCl₃)：δ3.9528(s，6H，CH₂)4.69983(s, 3H, OH) melting Point: 127 DEG C

Preparation of 22-nitro-2-methanesulfonic acid carbomethoxy-1, 3-methanesulfonic acid propylene diester

12.4g of methanesulfonyl chloride was dissolved in 30ml of pyridine solvent, cooled to below-5 ℃ and then slowly added dropwise to 5ml of pyridine solution containing 4.53g of 2-nitro-2-hydroxymethyl-1, 3-propanediol, reacted at 0 ℃ for 14 hours, added to water to give a yellow solid, and recrystallized from ethanol to give 7.51g of colorless crystals with a yield of 65%.

The product analysis data is as follows:

IR：3025cm^-1、2935cm^-1is C-N telescopic vibration, 1565cm^-1Vibration of C ═ O, 1350cm^-1C-O vibration of ester, 1175cm^-1、1020cm^-1Is the stretching vibration of S-O-C.

¹H NMR(CD₃COCD₃)：δ3.26(s，9H，CH₃)4.85(s，6H，CH₂) Melting point: 108 deg.C

Preparation of 32-methylsulphonic acid methyl ester-1, 3-methane sulphonic acid propane diester

In N₂Under the protection of gas, CH₃S^-Na⁺(10g, 150mmol) in 150ml DMSO, adding 19.25(50mmol) 2-nitro-2-methanesulfonic acid carbomethoxy-1, 3-methanesulfonic acid propane diester, reacting for 10h, irradiating with 20-W fluorescent lamp, adding into water, extracting with pentane, washing the extract with water, and MgSO 2₄Drying and distillation under reduced pressure gave 13.6g of a solid in 80% yield.

¹H NMR(CDCl₃)：δ2.68(s，1H，H)3.08(s，9H，CH₃)4.35(d，6H，CH₂)

Meltingpoint: 84 deg.C

42-azidomethyl-1, 3-diazidopropane

6.8g (0.02mol) of 2-methanesulfonic acid carbomethoxy-1, 3-methanesulfonic acid propylene diester is dissolved in 30ml of DMF, the mixture reacts for 72 hours at 70 ℃, TLC (thin layer chromatography) tracking reaction is carried out, after the raw material points completely react, the reaction liquid is put into deionized water, oil is collected, the oil is washed by the deionized water for a plurality of times, ether is extracted, extract liquid is collected, the solvent is distilled off, and silica gel column chromatography (ethyl acetate/petroleum ether) is carried out to obtain 1.75g of yellow liquid, namely the product.

The elements comprise: calcd for C26.52, N69.61, found C25.36, N70.21

Claims

1 an alkane containing three azides, the structural formula of which is R-C (CH)₂N₃)₃(R＝H)。

A process for the preparation of a compound according to claim 1, characterized in that it comprises the following steps:

1) reacting nitromethane and paraformaldehyde in an ethyl acetate solution, and preparing 2-nitro-trimethylolmethane by using a KOH catalyst;

2) reacting 2-nitro-trimethylolmethane with methanesulfonyl chloride at a low temperature to obtain a trimethanesulfonate of the compound;

3)N₂under the protection of gas, use CH₃S^-Na⁺Reducing 2-nitro-2-methyl-p-methanesulfonate-1, 3-propylene-p-methanesulfonate to reduce the nitro group to hydrogen atoms;

4) 2-p-methylsulfonyl-1, 3-di-p-methylsulfonyl propane diester and NaN₃The reaction is carried out under different temperature conditions, the optimal reaction conditions are found by tracking the reaction through thin-layer chromatography, and the 2-azidomethyl-1, 3-diazidopropane is obtained by carrying out column chromatography separation through a silica gel column.

3 triazoalkyl compounds R-C (CH)₂N₃)₃(R＝CH₃) The preparation method is characterized by comprising the following steps:

1) formaldehyde and acetaldehyde are subjected to aldol condensation reaction under an alkaline condition, and pure trimethylolethane is obtained by a recrystallization method;

2) at low temperature, the trimethylolethane reacts with p-toluenesulfonyl chloride to obtain tri-p-toluenesulfonate of the compound;

3) 2-methyl-2-p-toluenesulfonate carbomethoxy-1, 3-di-p-toluenesulfonate propylene diester and NaN₃Carrying out reaction at different temperatures, tracking the reaction by thin layer chromatography to find out the optimal reaction condition, and carrying out column chromatography separation by using silica gel column to obtain 2-Methyl-2-azidomethyl-1, 3-diazidopropane.