4-Toluenesulfonyl chloride → cis 4-Thiocyanatomethyl-3-[2-(2-tritylamino-4-thiazolyl)-2-methoxyimino-acetamido]-2-oxo-azetidine

Participants

Reaction Steps

1 ml of triethylamine and then 1.38 g of tosyl chloride were added to a suspension of 3.19 g of the syn isomer of 2-(2-tritylamino-4-thiazolyl)-2-methoxyimino-acetic acid in 50 ml of methylene chloride and the mixture was stirred at room temperature for 40 minutes. A solution of 1.162 g of the product of Step C in 40 ml of methylene chloride and 2 ml of trietylamine were added to the mixture over 5 minutes and the mixture was stirred for 4 hours, was washed with water, then with water containing 4 ml of N hydrochloric acid, dried and evaporated to dryness. The residue was dissolved in ethyl acetate and the solution was iced and vacuum filtered. The product was washed with methanol and dried to obtain 0.709 g of racemate of syn isomer of cis 4-thiocyanatomethyl-3-[2-(2-tritylamino-4-thiazolyl)-2-methoxyimino-acetamido]-2-oxo-azetidine. The mother liquors were evaporated to dryness and the residue was chromatographed over silica gel. Elution with a 93-7 chloroform-methanol mixture yielded another 1.069 g of the said product.

Provenance & Evidence