4-Thiazolecarboxamide, 5-bromo-2-methyl- synthesis

Yield:936477-33-7 79%

Reaction Conditions:

Stage #1: 5-bromo-2-methyl-1,3-thiazole-4-carboxylic acidwith 1,1'-carbonyldiimidazole in N,N-dimethyl-formamide at 60; for 2 h;
Stage #2: with ammonia in N,N-dimethyl-formamide at 20;

Steps:

B.3

Step 3: 5-Bromo-2-methyl-thiazole-4-carboxylic acid amide 5-Bromo-2-methyl-thiazole-4-carboxylic acid (14.4 g, 64.8 mmol) was dissolved in 100 ml DMF and CDI (11.6 g, 71.3 mmol) was added. The solution was stirred for 2 hrs at 60° C., cooled and NH₄OH (150 ml, 973 mmol) was added. The reaction mixture was stirred over night at room temperature and extracted two times with ethyl acetate and water. The organic extracts were washed four times with water, dried with sodium sulfate, filtered and evaporated. The crude product (11.3 g, 79%) [MS: m/e=222.8 (M+H⁺)] was used without any further purification for the next step.

References:

US2007/105891,2007,A1 Location in patent:Page/Page column 10