Allyl bromide → 2-[4,5-Dimethoxy-2-(morpholine-4-sulfonyl)-phenyl]-pent-4-enoic acid benzyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of [4,5-dimethoxy-2-(morpholine-4-sulfonyl)-phenyl]-acetic acid benzyl ester (3.00 g, 6.89 mmol) in anhydrous tetrahydrofuran (50 cm3) under an atmosphere of dry nitrogen cooled to −78° C. in an dry ice/acetone bath was added a 1 M solution of lithium bis(trimethylsilyl)amide (7.60 cm3, 7.60 mmol) in tetrahydrofuran dropwise over 5 minutes. The mixture was warmed to 0° C. in an ice bath for 30 minutes to dissolve all solids and cooled again to −78° C. in an dry ice/acetone bath. Neat allyl bromide (0.720 cm3, 8.27 mmol) was added at −78° C. over 5 minutes and the solution warmed to ambient temperature over 2 hours. Saturated ammonium chloride solution (30 cm3) was added and extracted with ethyl acetate (3×40 cm3). The combined ethyl acetate extracts were washed with brine solution (30 cm3), dried over sodium sulfate, vacuum filtered and the filtrate volatile fractions removed in vacuo to afford the title compound as a golden oil (3.25 g, 99.4%) with a positive ion ESI (M+H)+476.3.

Provenance & Evidence