Sodium hydride → Methyl 2-bromoimidazo[5,1-b]thiazole-7-carboxylate

Methyl isocyanoacetate (0.63 ml, 6.9 mmol) was gradually added dropwise to a suspension of sodium hydride (60% in mineral oil, 346 mg, 8.6 mmol) in N,N-dimethylformamide (5 ml) in an argon atmosphere under ice cooling, and the mixture was stirred at the same temperature for 2 hr. This solution was added dropwise to a solution of 2,5-dibromothiazole (1.0 g, 4.1 mmol) in tetrahydrofuran (10 ml) cooled to −20° C. (brine/ice water) through a cannula over a period of 15 min, and, while allowing the temperature to rise to about 0° C., the mixture was stirred for 2 hr. After the completion of the reaction, saturated brine was added thereto, and the mixture was extracted with dichloromethane (20 ml×5). The organic layer was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under the reduced pressure. The residue was washed with ethyl acetate to give methyl 2-bromoimidazo[5,1-b]thiazole-7-carboxylate (910 mg, 85%) as a white solid.

1. customto rise to about 0° C.
2. stirringthe mixture was stirred for 2 hr
3. additionwas added
4. extractionthe mixture was extracted with dichloromethane (20 ml×5)
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. customthe solvent was removed by distillation under the reduced pressure
7. washThe residue was washed with ethyl acetate

ORD record

ord-8cdb44a7b92f4cd7a999fa59bf49e02b

Source dataset

uspto-grants-2010_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07662841B2