Ethyl chloroformate → HCID 54275443, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 4.66 g (20 mmol) of N-Boc-thioproline and 3.84 mL (22 mmol) DIEA dissolved in 10 mL THF was cooled to 0_C and treated with 2.1 mL (22 mmol) of ethyl chloroformate. After 30 min at RT the white precipitate is filtered off, the solution cooled to 0° C. and a solution of 8.32 g (220 mmol) sodium borohydride in 30 mL H2O is added dropwise. The reaction was stirred for 24 h, then cooled to 0° C. and quenched by dropwise addition of acetic acid. The product was then extracted with EtOAc, the combined organics were washed successively with sodium bicarbonate and citric acid, dried with magnesium sulfate, filtered and solvents removed in vacuo to provide 2.33 g of the title compound: MS (ES+) m/e 242 (M+23), 120 (M-Boc+1).

Provenance & Evidence