The synthetic method of 1-methyl-3,3-diphenylurea

Abstract

The invention discloses a synthesis method of 1-methyl-3,3-diphenylurea. The invention uses diphenylamine as a raw material and comprises the following steps: ① adding dichloromethane, pyridine and diphenylamine into a reaction bottle, and 10℃~45℃, add dropwise solid phosgene-dichloromethane solution under stirring, and react for 2h~6h after dropping, wherein the molar ratio of dichloromethane, diphenylamine, pyridine and solid phosgene is 4~8:0.37~ 0.74: 0.37~0.74: 0.12~0.25; ②Add the dianilinocarbonyl chloride and triethylamine obtained in step ① into the reaction bottle, and react with methylamine gas at a temperature of 20°C-45°C for 0.5h-4h. Wherein the mol ratio of dichloromethane, dianilino carbonyl chloride, triethylamine and methylamine is 4~8: 0.37~0.74: 0.37~0.74: 0.37~0.74, the present invention is mainly used for 1-methyl-3,3 - Synthesis of diphenylurea.

Description

technical field [0001] The invention relates to a synthesis method of 1-methyl-3,3-diphenylurea (AK-II), which belongs to organic synthesis. Background technique [0002] 1-Methyl-3,3-diphenylurea is an important stabilizer for propellant and solid propellant. The synthesis method of AK-II is mostly through the reaction of diphenylamine and gaseous phosgene or cyanogen chloride to synthesize the intermediate dianilinocarbonyl chloride, and dianilinocarbonyl chloride is reacted with methylamine in acetone or toluene to synthesize AK-II. In the known synthetic methods of AK-II, the reaction is mostly carried out under the conditions of poor process safety, high energy consumption, long reaction cycle and high solvent toxicity. For example Robinson J R, Brown W H and Ontario A C etc. disclose a kind of synthetic method of AK-II in " Diphenylcyanamide derivatives " Canadian Journal of Chemistry, 1951,29:1069-1074, and this method uses cyanogen chloride (toxicity is bigger, prep...

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Problems solved by technology

In the known synthesis methods of AK-II, the reaction is mostly carried out under the conditions of poor process safety, high energy consumption, long reaction cycle and high solvent toxicity

For example Robinson J R, Brown W H and Ontario A C etc. disclose a kind of synthetic method of AK-II in " Diphenylcyanamide derivatives " Canadian Journal of Chemistry, 1951,29:1069-1074, and this method uses cyanogen chloride (toxicity is bigger, preparation difficulty, poor stability, high cost) and diphenylamine through three-step reaction of cyanation, acylation and chlorination to produce the intermediate dianilinyl carbonyl chloride with a yield of 54%; then, the intermediate is dissolved in ether, Pass into methylamine gas, obtain AK-II, yield 78%; The total yield of this method is 42%, but this method reaction step is more, and overall reaction yield is lower