Methyl chloroformate → Methyl 4-chlorothieno[2,3-d]pyrimidine-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of THF (50 mL) and Hünig's base (2.14 mL, 15.2 mmol) were cooled to −78° C. and n-BuLi (2.5 M in hexanes, 5.7 mL, 14.1 mmol) added drop wise. The solution was warmed to 0° C. for 10 minutes, re-cooled to −78° C. and 4-chlorothieno[2,3-d]pyrimidine (2.0 g, 11.7 mmol) added. The anion was stirred for 10 minutes at −78° C., methyl chloroformate (1.0 mL, 12.9 mmol) added drop wise and the reaction maintained at −78° C. for 0.5 hours. The reaction was allowed to warm to ambient temperature. After 1 hour, the mixture was poured into saturated aqueous ammonium chloride (50 mL) and extracted with EtOAc (4×50 mL). The combined organic layers were dried (Na2SO4), filtered and concentrated in vacuo. The crude product was purified by flash-column chromatography (100% DCM) to yield yellow solid (0.256 g, 10%).

Provenance & Evidence