tert-Butyl bromoacetate → HCID 131712396, compound

Participants

Reaction Steps

0.5 g of silver oxide were added at 20° C. to a mixture of 0.074 g of the product of Step B, 0.7 ml of dimethylformamide and 0.5 ml of tert.-butyl bromoacetate and the mixture was stirred for 30 minutes and was vacuum filtered. The filter was rinsed with ethyl acetate and the filtrate was added to 10 ml of water. The mixture was decanted and the aqueous phase was extracted with 5 ml of ethyl acetate. The combined organic phases were washed with 5 ml of aqueous sodium chloride solution, dried over magnesium sulfate and was vacuum filtered. The filter was rinsed with ethyl acetate and the filtrate was evaporated to dryness. The residue was taken up in isopropyl ether and efflorescenced. The mixture was vacuum filtered and the product was rinsed with isopropyl ether and dried to obtain 0.02 g of the syn isomer of tert.-butyl 7-[2-(2-tritylamino-4-thiazolyl)-2-(tert.-butoxycarbonylmethoxyimino)-acetamido]-3-acetoxymethyl-ceph-3-eme-4-carboxylate with Rf=0.34 (methylene chloride containing 5% ether). The product was identical to the product of Example 3.

Provenance & Evidence