Ammonium Hydroxide → 4-Methoxy-7-morpholin-4-yl-benzothiazole-2-carboxylic acid amide

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Reaction Steps

A suspension of 3.51 g 4-methoxy-7-morpholin-4-yl-benzothiazole-2-carboxylic acid and 1.78 g 1,1′-carbonyl-diimidazol in 30 ml DMF was stirred at room temperature for 18 hours. 0.8 ml Ammonium hydroxide (25% in water) was added and stirring was continued for 5 hours. Extraction with water/ethylacetate and crystallization from dichloromethane yielded 1.17 g (40%) 4-methoxy-7-morpholin-4-yl-benzothiazole-2-carboxylic acid amide as a yellow solid; M.p.: 228–231° C.; MS (ISP): m/e=294 (M+H+). To a solution of 4.67 g 4-methoxy-7-morpholin-4-yl-benzothiazole-2-carboxylic acid amide and 2.18 g imidazole in 95 ml pyridine were added at 0° C. 5.95 ml phosphoroxychloride. After 5 hours the cold solution was diluted with ethylacetate and extracted with water. The organic solution was dried with sodiumsulfate and the solvents were distilled off to yield 3.94 g 4-methoxy-7-morpholin-4-yl-benzothiazole-2-carbonitrile as yellow solid; M.p.: 145–147° C.; MS (ISP): m/e=276 (M+H+).

Provenance & Evidence