Pyridine → (3aS,7S,7aS)-rel-6-(2,4-dimethoxy-benzyl)-7-(2-fluoro-phenyl)-7-methyl-hexahydro-2,4-dioxa-5-thia-6-aza-indene 5-oxide

Participants

Reaction Steps

Under a dry atmosphere of argon, a solution of rel-(3S,4S)-4-[(S)-1-(2,4-dimethoxy-benzylamino)-1-(2-fluoro-phenyl)-ethyl]-tetrahydro-furan-3-ol (6.8 g, 18.1 mmol) in pyridine (7.32 ml, 90.5 mmol) and dichloromethane (120 ml) was cooled to −77° C. The colorless solution was treated dropwise with thionyl chloride (2.15 g, 18.1 mmol) over about 10 minutes while the temperature rose to −73° C. After removal of the cooling bath the reaction mixture was allowed to reach room temperature. For the workup, the reaction mixture was diluted with dichloromethane (150 ml) and washed consecutively with hydrochloric acid (1N) and a saturated solution of sodium hydrogencarbonate. The organic layer was dried over sodium sulphate and evaporated. The (3aS,7S,7aS)-rel-6-(2,4-dimethoxy-benzyl)-7-(2-fluoro-phenyl)-7-methyl-hexahydro-2,4-dioxa-5-thia-6-aza-indene 5-oxide (7.24 g, 95% yield) was obtained as a white solid. MS (ISP): m/z=422.0 [M+H]+.

Provenance & Evidence