CN106543026A

CN106543026A - A kind of preparation method of methyl hydrazine

Info

Publication number: CN106543026A
Application number: CN201610929564.2A
Authority: CN
Inventors: 李亚杉
Original assignee: Chongqing Jinshan Science and Technology Co Ltd
Current assignee: Shijiazhuang Jinpai Pharmaceutical Chemical Co. Ltd.
Priority date: 2016-10-31
Filing date: 2016-10-31
Publication date: 2017-03-29
Anticipated expiration: 2036-10-31
Also published as: CN106543026B

Abstract

The invention discloses a kind of method that one-step method prepares methyl hydrazine; the method is under inert gas shielding; hydrazine hydrate and methanol are alkylated into reaction one-step synthesis methyl hydrazine under catalyst action; methanol excess, the mixed liquor after reaction is terminated is kept to obtain highly purified methyl hydrazine solution by rectification during the course of the reaction.The invention has the advantages that：Process route is short, simple to operate, and reaction yield is high；Catalyst choice is high, and reaction condition is gentle, and side reaction and by-product are few；Catalyst and unreacted methanol, hydrazine hydrate are circularly used for alkylated reaction, do not use solvent, three wastes to produce, environmental protection.

Description

A kind of preparation method of methyl hydrazine

Technical field

The invention belongs to chemosynthesis technical field, and in particular to a kind of preparation method of methyl hydrazine.

Background technology

Methyl hydrazine is a kind of important energy and material, meanwhile, and synthesize some high-quality pesticide, the important centre of medicine Body.It is many for the preparation method report of methyl hydrazine, following several preparation methoies are mainly had according to existing document：

Chloramine method：Patent US4192819 discloses the technique of chloramine method synthesizing methyl hydrazine earliest, mainly adopts sodium hypochlorite and ammonia Then chloramines is generated methyl hydrazine with monomethyl amine reaction by reaction production chloramines.Technique is ripe, but the route later separation Difficulty is big, production process high energy consumption, equipment cost are big.

Hydrazine hydrate benzaldehyde method：Benzal azine, then plus sulphuric acid two are generated with benzaldehyde reaction by raw material of hydrazine hydrate Methyl ester generates methylhydrazinium sulphate, in Jing Sodium ethylate and rectification.Product yield 60% ~ 70%.But whole reaction raw materials cost compared with It is high, course of reaction is more complicated, energy consumption is larger, abnormal smells from the patient is larger in production process, is unfavorable for industrialized production.

Dimethylphosphite or dimethyl carbonate hydrazine hydrate method：Methylated examination with dimethylphosphite or dimethyl carbonate Agent, is directly synthesized methyl hydrazine in atmospheric conditions with hydrazine hydrate, according to the literature the optimum reaction condition of this technique synthesis, a first The reaction yield of base is 50%, but same selected methylating reagent price is higher, and reaction yield is comparatively relatively low.

One hydrazinoethanol decomposition method：Decompose to prepare MMH by the thermodynamics of 2-hydrazinoethanol, be prepared by one kind The new method of MMH, 2-hydrazinoethanol is positioned in reactor, is heated to 200 ~ 225 DEG C so as to decompose, liquid point The further vacuum distillation of solution product separates the azeotropic mixture for obtaining water and methyl hydrazine, then takes with desiccant dryness such as NaOH, enters one Walk air-distillation to obtain methyl hydrazine.The technological advantage is that reaction is simple, and purification is easier to.Have the disadvantage that hydrazinoethanol decomposes easily to produce Life split it is quick-fried, react it is unstable, there is serious potential safety hazard in production process.

N- nitro methylamine hydrogenation methods：N- nitro methylamines are in the case where catalyst is made with palladium, by hydrogenation reduction, raw Into mixture in, MMH can by plus appropriate acid form acid hydrazine, separated go out MMH aqueous solution, root According to needing to carry out purification concentration again.The method advantage is that raw material is easy to get, low production cost.Have the disadvantage to need high pressure, and palladium to urge Agent is relatively costly, is adapted to small-scale experiment production, is unfavorable for large-scale industrial production.

Dimethyl sulfate hydrazine hydrate method：Patent CN101402586A discloses one kind by hydrazine hydrate and dimethyl sulfate with salt Used as protective agent, tetrabutyl ammonium bromide generates methylhydrazinium sulphate at 115 ~ 125 DEG C as catalyst, then in highly basic hydrogen for acid Methyl hydrazine solution under sodium oxide the condition of dissociation needed for rectification is isolated.This method raw material is easy to get, cheap, anti- The advantages of answering fast speed, high income.But dimethyl sulfate toxicity is larger to have potential safety hazard, while can remain after free end A large amount of intractable sodium salts, this undoubtedly increased sodium salt processing cost and brings cumbersome environmental issue, therefore this set Technique is difficult to carry out industrialized production.

Hydrazine hydrochloride methanol method：Patent CN102516117B is disclosed one kind and is reacted with methanol under high pressure with hydrazine hydrochloride, then With the free methyl hydrazine hydrochloride of hydrazine hydrate, then through distilling the method for producing methyl hydrazine with rectification process.The method step is more, instead Answer pressure high, equipment investment is big, can produce more by-product 1,2- dimethylhydrazines.

Monochloro methane hydrazine hydrate method：Patent CN105037196A discloses a kind of side of catalytic synthesis of methyl hydrazine under normal pressure Method.It is characterized in that：Hydrazine hydrate and monochloro methane are made into protective agent with hydrochloric acid, silica gel makees catalyst, ethanol as solvent, 70 ~ 74 DEG C Lower synthesis under normal pressure, generates methyl hydrazine hydrochloride, then is dissociated methyl hydrazine with hydrazine hydrate, and it is water-soluble that Jing rectification process obtains methyl hydrazine Liquid.The method reactions steps are more, need recycling design and catalyst, high energy consumption, hydrochloric acid that there are corrosivity to have high demands to equipment.

The content of the invention

For the disadvantages mentioned above for overcoming prior art to exist, the invention provides a kind of process route is short, by-product is few, receive Rate height, the cheap prices of raw materials, energy-conserving and environment-protective, the methyl hydrazine novel preparation method of economic security.

The technical solution used in the present invention is：Following steps are carried out under inert gas shielding：

1st, methanol and hydrazine hydrate are put in reactor, catalyst sodium sulfite and to toluene sulphur is then added in reactor Sour sodium, closed reactor are warming up to 70-100 DEG C and are alkylated reaction, and the response time is 3-5 hours, is obtained containing methyl The mixed liquor of hydrazine.During the course of the reaction, the mol ratio that should keep methanol excess, methanol and hydrazine hydrate is 1-2: 1, sodium sulfite Addition with paratoluenesulfonic acid sodium salt is respectively 5%-the 30% of hydrazine hydrate quality, and its reaction equation is as follows：

CH₃OH + NH₂NH₂·H₂O —→ CH₃NHNH₂ + 2H₂O

2nd, the methyl hydrazine mixed liquor for obtaining step 1 is proceeded in rectifying still after being cooled to 60 DEG C, is to slowly warm up to boiling, in temperature The methanol for steaming is collected at 65-70 DEG C, 90-100 DEG C are continuously heating to, the methyl hydrazine that steams is collected, rectification terminate after by kettle Substrate（Sodium sulfite, p-methyl benzenesulfonic acid sodium catalyst and unreacted hydrazine hydrate）The anti-of step 1 is proceeded to the methanol for steaming It is used for alkylated reaction in answering kettle.

The present invention is, under inert gas shielding, hydrazine hydrate and methanol to be alkylated under catalyst action reaction one Step synthesizing methyl hydrazine, keeps methanol excess, the mixed liquor after reaction is terminated to obtain high-purity by rectification during the course of the reaction Methyl hydrazine solution, while reclaiming unreacted methanol, hydrazine hydrate and catalyst, they are continued on for into alkylated reaction and are produced Methyl hydrazine.Compared with prior art, the invention has the beneficial effects as follows：（1）Course of reaction is simple, and process route is short, reaction yield Height, reaches more than 95% with hydrazine hydrate rate of collecting；（2）Catalyst choice is high, and the growing amount of many alkylate by-products is few；（3） Catalyst and unreacted methanol, hydrazine hydrate are recycled for alkylated reaction, do not use solvent, three wastes to produce, green ring Protect；（4）Hydrazonium salt is substituted with free hydrazine be alkylated reaction and reduce reaction temperature, the decomposition and side reaction for reducing hydrazine is sent out It is raw, save energy consumption.

Specific embodiment

Described below percentage composition is mass fraction, and the yield of methyl hydrazine is with the consumption gauge of hydrazine hydrate, all steps Complete under inert gas shielding.

Embodiment 1

360g methanol and hydrazine hydrate that 625g concentration is 80% are put in reactor, then by 53g sodium sulfitees and 82g pair Toluenesulfonic acid sodium salt is added in reactor, closed reactor, is opened stirring, is warming up to 86 DEG C, and reaction will react liquid temperature after 5 hours Degree drops to 60 DEG C, reactant liquor is proceeded to and be warming up in rectifying still 65-70 DEG C, steamed methanol 87g, be continuously heating to 90-110 DEG C, steam methyl hydrazine 393g.Rectification contains hydrazine hydrate 55g in terminating rear bottoms, methyl hydrazine yield is 96.1%.

Embodiment 2

The methanol 87g and the bottoms containing hydrazine hydrate 55g that rectification in embodiment 1 is reclaimed is proceeded in reactor, supplements 393g Then 33g sodium sulfitees and 25g paratoluenesulfonic acid sodium salts are added to reactor by methanol and the hydrazine hydrate that 742g concentration is 60% In, closed reactor is opened stirring, is warming up to 98 DEG C, and reacting liquid temperature was dropped to 60 DEG C after 3 hours by reaction, and reactant liquor is turned 65-70 DEG C are warming up in entering rectifying still, methanol 196g are steamed, is continuously heating to 90-110 DEG C, steam methyl hydrazine 405g.Rectification Contain hydrazine hydrate 48g after end in bottoms, methyl hydrazine yield is 97.3%.

Embodiment 3

The methanol 196g and the bottoms containing hydrazine hydrate 48g that rectification in embodiment 2 is reclaimed is proceeded in reactor, is supplemented 284g methanol and the hydrazine hydrate that 753g concentration is 60%, closed reactor are opened stirring, are warming up to 95 DEG C, will after reacting 3 hours Reacting liquid temperature drops to 60 DEG C, reactant liquor is proceeded to and be warming up in rectifying still 65-70 DEG C, steams methanol 200g, is continuously heating to 90-110 DEG C, steam methyl hydrazine 399g.Rectification contains hydrazine hydrate 52g in terminating rear bottoms, methyl hydrazine yield is 96.9%.

Embodiment 4

The methanol 200g and the bottoms containing hydrazine hydrate 52g that rectification in embodiment 3 is reclaimed is proceeded in reactor, is supplemented Then 45g sodium sulfitees and 39g paratoluenesulfonic acid sodium salts are added to instead by 376g methanol and the hydrazine hydrate that 1120g concentration is 40% In answering kettle, closed reactor is opened stirring, is warming up to 75 DEG C, and reacting liquid temperature was dropped to 60 DEG C after 4 hours by reaction, will reaction Liquid is warming up to 65-70 DEG C in proceeding to rectifying still, steams methanol 285g, is continuously heating to 90-110 DEG C, steams methyl hydrazine 414g. Rectification contains hydrazine hydrate 42g in terminating rear bottoms, methyl hydrazine yield is 98.2%.

Claims

1. a kind of preparation method of methyl hydrazine, it is characterised in that：Following steps are carried out under inert gas shielding：

（1）Methanol and hydrazine hydrate are put in reactor, catalyst sodium sulfite and to toluene is then added in reactor Sodium sulfonate, closed reactor are warming up to 70-100 DEG C and are alkylated reaction, and the response time is 3-5 hours, is obtained containing first The mixed liquor of base hydrazine；

（2）By step（1）The methyl hydrazine mixed liquor for obtaining is proceeded in rectifying still, is to slowly warm up to boiling, in 65-70 DEG C of temperature It is lower to collect the methanol that steams, be continuously heating to 90-100 DEG C, collect the methyl hydrazine for steaming, rectification terminate after by bottoms and steaming The methanol for going out proceeds to step（1）Reactor in be used for alkylated reaction.

2. the preparation method of a kind of methyl hydrazine according to claim 1, it is characterised in that：The step（1）In, methanol and The mol ratio of hydrazine hydrate is 1-2: 1, the addition of sodium sulfite and paratoluenesulfonic acid sodium salt respectively for hydrazine hydrate quality 5%- 30%。