Methylamine → (2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonic acid methylamide

Participants

Reaction Conditions

Reaction Steps

SO2NHR (via NSO2Cl) Following a procedure described in U.S. Pat. No. 4,868,308: 2.12 ml (21.5 mmol) Alpha-picoline and 0.19 ml (2.8 mmol) chloro sulfonic acid were added at −10° C. to 30 ml 1,2-dimethoxyethane, warmed up to 10° C. and treated with 431 mg (0.93 mmol) of (2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine. The reaction was stirred at room temperature over night, treated with 0.32 ml (3.5 mmol) POCl3 and after 4 h at room temperature with 5 ml 8.03 M MeNH2 in EtOH. The reaction was stirred over night and extracted with aqueous 10% KHSO4/EtOAc (3×), the organic phases were washed with 10% NaCl. The crude product was crystallized from CH2Cl2/Et2O at −20° C. to give 147 mg (28%) of (2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonic acid methylamide, mp 140–142° C., MS: 581 (M+Na+).

Provenance & Evidence