Tetrahydrofuran → p-Nitrobenzyl (4-tert-butylthio-2-oxo-1-azetidinyl)acetate

Participants

Reaction Conditions

Reaction Steps

14.4 ml of a 1N solution of lithium bistrimethylsilylamide in tetrahydrofuran (THF) are added dropwise to a stirred solution of 1.91 g (12 mmol) of tert-butylthioazetidin-2-one in 6 ml of dry N,N-dimethylformamide (DMF) at -70° C., and a solution of 4.93 g (18 mmol) of p-nitrobenzyl bromoacetate in 6 ml of DMF is subsequently added dropwise to the mixture, and the mixture is then stirred for a further 30 minutes at -30° C. The reaction mixture is diluted with 100 ml of toluene and washed with three 50 ml portions of water, the organic phase is dried over magnesium sulphate, and the solvent is evaporated in vacuo to give 4.3 g of a solid crude product, which is chromatographed over 120 g silica gel using toluene:ethyl acetate (4:1). The purified product (2.6 g) is recrystallized from 100 ml of dry isopropanol. Yield 2.09 g of melting point 82.5°-84° C. IR spectrum in methylene chloride: 2955, 1770, 1755, 1610, 1530, 1390, 1375, 1365, 1345, 1180, 1110, 945, 915, 855, 845 cm-1.

Provenance & Evidence