反应详情

温度

10 °C

A solution of (2-methoxy-5-morpholin-4-yl-phenylamino)-thioxo-acetic acid (4) in 1N NaOH is added to a solution of potassium ferricyanide in water at a rate that the temperature does not exceed 10° C. The mixture is stirred for 3 hours at 10° C. and concentrated hydrochloric acid is added until pH 1 was reached. Filtration of the precipitate and drying yielded 4-methoxy-7-morpholin-4-yl-benzothiazole-2-carboxylic acid (5). A suspension of the compound of formula (5) and 1.1′-carbonyl-diimidazole in dimethylformamide is stirred at room temperature for about one hour. A compound of formula (6), for example benzylamine, is added, stirring is continued and after about 20 hours water is added. After extraction with ethyl acetate and chromatography on silicagel with dichloromethane/ethyl acetate is yielded a compound of formula I.

1. customdoes not exceed 10° C
2. filtrationFiltration of the precipitate
3. customdrying