US 12,668,588 B2Granted

Method for preparing intermediate of uracil compound containing isoxazoline

AssigneesShenyang Sinochem Agrochemicals R&D Co., Ltd., Jiangsu Yangnong Chemical Co., Ltd.

InventorsEnming Wu, Gongxin Wu, Chunrui Yu, Qiao Wu, Jichun Yang, Yanming Ye, Fuqiang Yu, Youren Xue, Aiying Guan

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Abstract

A method for preparing an intermediate of a uracil compound containing isooxazoline includes the steps of: making 3-amino-4,4,4-trifluorocrotonic acid methyl ester react with substituted aryl carbamate; in a reaction process, continuously evaporating water and byproduct alcohol in the system; and conducting processing to obtain the intermediate of the uracil compound containing isooxazoline. Using this method the selectivity of the reaction and the utilization rate of raw materials are improved; the hydrolysis products, impurities and tar are reduced; the reaction time is greatly shortened; and the productivity is improved. After one recrystallization of crude products, an intermediate product with purity of more than 97% can be obtained, and quantitative yield can be more than 85%.

Claims11

Dependent claims

A method for preparing an intermediate of a uracil compound containing isooxazoline, comprising:

reacting a compound of formula III with a compound of formula IV in the presence of a catalyst;
and
continuously removing water and alcohol generated in the reaction by evaporation to obtain the intermediate of the uracil compound containing isooxazoline of formula II:
wherein:
R1 and R2 are the same or different, and are independently selected from hydrogen, fluorine, and chlorine;
R3 is hydrogen or C1-C4 alkyl;
R4 is hydrogen, CO2R7, or CH2OR8;
R5 is hydrogen, CO2R7, or CH2OR8;
R6 is hydrogen, C1-C4 alkyl, or C1-C4 haloalkyl;
R7 is C1-C4 alkyl, C1-C4 haloalkyl, allyl, or propargyl;
R8 is hydrogen, C1-C4 alkyl, C1-C4 haloalkyl, or C1-C4 alkyl carbonyl;
R9 is C1-C4 alkyl;
R10 is C1-C4 alkyl, and
the catalyst is 1,8-diazabicyclo[5.4.0]undec-7-ene or a salt thereof.

11 more elements

Dependencies are inferred from the claim text.