Bromine → 5-Bromo-2-methyl-1,3-thiazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

2-Methyl-thiazole-4-carboxylic acid (13.0 g, 90.8 mmol) was dissolved in 750 ml THF and cooled to −75° C. n-BuLi (1.6M in THF; 120 ml, 190.7 mmol) was added dropwise in 30 minutes. The red suspension was stirred for 15 min. at −75° C. and 30 min. at 0° C. A solution of bromine (5.1 ml, 100 mmol) in 20 ml cyclohexane was added dropwise at −75° C. and stirring was continued at room temperature for 2 hrs. The reaction mixture was quenched with 20 ml water, evaporated and acidified with 2N HCl to pH 2. The aqueous layer was extracted two times with ethyl acetate. The combined organic extracts were dried with sodium sulfate, filtered and evaporated. The crude product (16.4 g, 81%) [MS: m/e=223.0 (M+H+)] was used without any further purification for the next step.

Provenance & Evidence