5-bromo-2-methylthiazole-4-carbonitrile synthesis

Yield:723743-71-3 62%

Reaction Conditions:

with triethylamine;trifluoroacetic anhydride in dichloromethane at 0; for 2 h;

Steps:

B.4

Step 4: 5-Bromo-2-methyl-thiazole-4-carbonitrile 5-Bromo-2-methyl-thiazole-4-carboxylic acid amide (11.3 g, 51.1 mmol) was dissolved in 150 ml dichloromethane and triethylamine (14.2 ml, 102.2 mmol) was added. Trifluoroaceticanhydride (14.3 ml, 102.2 mmol) was added dropwise at 0° C. and the mixture stirred without cooling for 2 hrs. The reaction mixture was quenched with saturated NaHCO₃-solution and extracted with ethyl acetate. The organic extract was washed with brine, dried with sodium sulfate, filtered and evaporated. The crude product was purified by flash chromatography on silica gel (heptane/ethyl acetate 90:10->20:80 gradient). The desired compound was obtained as a light yellow solid (6.4 g, 62%), MS: m/e=204.0 (M+H⁺).

References:

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