CN1023865C

CN1023865C - Gynthetic process of phosphorus methylamine

Info

Publication number: CN1023865C
Application number: CN 91101697
Authority: CN
Inventors: 唐除痴; 吴桂萍
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 1991-03-18
Filing date: 1991-03-18
Publication date: 1994-02-23
Anticipated expiration: 2006-03-18
Also published as: CN1055538A

Abstract

Methamidophos is an organophosphorus insecticide with high efficiency and broad spectrum. In the present invention, O, O, O-trimethyl thiophosphate is used as a raw material, and methamidophos is obtained through isomerization chlorination and aminolysis. The product purity is as high as 91.3%, and the total yield in terms of the raw material reaches 72 to 78%. The technology has the advantages of convenient operation and high product content.

Description

The synthetic method of acephatemet

The chemical name of acephatemet (I) is the 0-methyl, S-methyl amido thiophosphatephosphorothioate, it is a kind of efficient of Bayer company exploitation at the beginning of the seventies, broad-spectrum organophosphorous pesticide, China is since the mid-1970s begins to put into production, output enlarges year by year, has now become one of organic phosphorous insecticide kind of China's scale operation, and its synthetic route is:

Because of this method raw material is easy to get and is easy to industrialization, generally adopt in the native land, but its main drawback is the content of acephatemet too low (having only about 70%), and productive rate also not high (counting 70%) with (IV), the reason that this method product content and productive rate do not increase is when carrying out isomerization reaction because of the employing methyl-sulfate, due to its transformation efficiency is generally not high.The impurity of product (up to 30%) mainly is some low molecule phosphides, its toxicity and use the back influence of environment be can not be ignored.

The objective of the invention is to seek a kind of method that can overcome the synthesis of methylamines phosphorus of above-mentioned shortcoming.

The present invention is to use 0,0, and 0-trimethyl phosphorothioate (III) is made raw material, separates two-step reaction through isomerization chlorination and ammonia, obtains content and be the acephatemet more than 90%, and its productive rate can reach 72-78% in (III):

Isomerization chlorination normally carries out 2-8 hour under 50 °-100 ℃, but preferably adopts 60 ℃ of reactions 5 hours.Raw material (III) and POCl ₃Mol ratio be 1: 1; When ammonolysis reaction, feed ammonia to pH=8-9, the solvent that uses can be alkyl chloride, as chloroform, methylene dichloride, ethylene dichloride etc., temperature of reaction-5 °-20 ℃ all can, but preferably adopt ℃.Raw materials used (III) can be easily from PSCl ₃React in the presence of solid caustic soda or sodium methylate with alcohol and to obtain, productive rate (in raw material) can reach 90% through last, and the content of (III) reaches more than 98%:

Adopt the advantage of this law synthesis of methylamines phosphorus to be that raw material is easy to get and its purity is good, need not hypertoxic Me ₂SO ₄, (acephatemet purity reaches more than 90% product, and overall yield is counted 72-78% with (III).

Example 1

With 0 of 7.8 grams (0.05 mole), 0,0-trimethyl phosphorothioate (III) and 7.7 restrained the phosphorus oxychloride of (0.05 mole) in 60 ℃ of stirring reaction 5-6 hours, question response thing cooling back adds 150 milliliters of ethylene dichloride, under agitation condition, feed ammonia in-2 °-2 ℃, when treating pH=8-9, progressively be warming up to 20-50 ℃ of restir then and react half an hour.Generate a large amount of white precipitates, the filter residue after the filtration washs with 25 milliliters of ethylene dichloride, obtains white solid 12 grams, filtrate is under reduced pressure steamed solvent, reclaim 160 milliliters of ethylene dichloride altogether, get faint yellow acephatemet product 6 grams, form little yellow solid after the cooling room temperature.Analyzing methylamine phosphate content through GC is 91.3%, and productive rate is that 77.7%[calculates by the charging capacity of (III)].

Example 2

Operation gets acephatemet 5.6 grams with example 1 but the charging capacity of ethylene dichloride changes 100 milliliters into, and content is 90.5%, and productive rate 71.9%[is by (III)].

Claims

1, the method for a kind of synthesis of methylamines phosphorus (I) is characterized in that it is to make raw material with (III), makes (I) through isomerization chlorination and ammonolysis reaction:

2, according to the method for the said synthesis of methylamines phosphorus of claim I (I), when it is characterized in that carrying out isomerization chlorination, raw material (III) and POCl ₃Mol ratio be 1: 1, reaction is to carry out 2-8 hour under 50 °-60 ℃.

3, press the method for the said synthesis of methylamines phosphorus of claim I, when it is characterized in that ammonolysis reaction, feed ammonia to pH=8-9, and use alkyl chloride (as ethylene dichloride) to make solvent, the amount of solvent is that every mole raw material (III) uses the 2000-3000 milliliter, and range of reaction temperature is-5 °-20 ℃.