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ChemicalBook CAS DataBase List Pentobarbital
76-74-4

Pentobarbital synthesis

3synthesis methods
-

Yield:76-74-4 99.6 g

Reaction Conditions:

with sodium methylate in methanol;ethyl acetate at 60 - 140;

Steps:

1.C; 2.C; 3.C; 4.C Step C:
139.7 g of a methanol solution containing 29% (W / W) sodium methoxide and 2.5 g of ethyl acetate were added to the reaction flask.The temperature was raised to 60 to 85 ° C to eliminate the reaction for 30 minutes.Added 60.6g of ureaAnd 129.2 g of ethyl- (1-methylbutyl) malonic acid diethyl ester, recovering formazan and ethanol by heating and distilling to 135-140 ° C,Then evaporated to dryness under reduced pressure (about 2 to 3 hours).The temperature was lowered below 20 ° C, and 517 g of cold water was added to dissolve.Add activated carbon to decolorize, filter,Hydrochloric acid acidified to pH 3-4, filtered,Drying gave 107.2 g of a crude 5-ethyl-5- (1-methylbutyl) barbituric acid.The crude 5-ethyl-5- (1-methylbutyl) barbituric acid was recrystallized from an aqueous solution of ethanol, filtered and washed.99.6g under vacuum drying5-ethyl-5- (1-methylbutyl) barbituric acid finished product,HPLC content was 99.87%.

References:

Shandong Xinhua Pharmaceutical Co., Ltd.;Zhu Lianbo;Xu Haojie;Zhao Shuai CN110256362, 2019, A Location in patent:Paragraph 0021; 0024; 0025; 0028; 0029; 0032; 0033; 0036

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