Methanol → benzyl N-(3-methoxy-2-oxoazetidin-3-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

A solution of 730 mg (0.0025 mole) of 1-chloro-3-[N-chloro-N-[(phenylmethoxy)carbonyl]amino]-2-azetidinone in 5 ml of tetrahydrofuran is cooled to -78° C. and 4 ml of methanol containing 285 mg of lithium methoxide is added. After 20 minutes at -78° C., 0.6 ml of acetic acid and 0.6 ml of trimethylphosphite are added. The solution is stirred for 5 minutes at -78° C., allowed to warm to ambient temperature and stirred for 30 minutes. The resulting solution is diluted with ethyl acetate, washed with 5% sodium bicarbonate, water, 5% potassium bisulfate, water, saturated salt solution, and dried. Solvent removal gives an oil that is applied to four 20×20 cm×1 mm silica gel plates. Development with benzene-ethyl acetate (1:1) and isolation of the major UV-active band of Rf=0.25 gives 91 mg of oil that crystallizes from ether to give a solid. Recrystallization from ether gives the title compound, melting point 112°-114° C.

Provenance & Evidence