Formic Acid → 7-[2-(2-aminothiazol-4-yl)-2-(2-aminoethoxyimino)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid

Participants

Reaction Steps

A mixture of 2 g of the product of Step B and 5 ml of formic acid was heated with stirring to 40°-45° C. and after the addition of 5 ml of water, the mixture was stirred at 40°-45° C. for 15 minutes and was then cooled. The mixture was vacuum filtered to remove triphenylcarbinol and the filtrate was evaporated to dryness under reduced pressure. The residue was taken up in 10 ml of ethanol with efflorescence and the mixture was vacuum filtered. The recovered product was rinsed with ethanol and then with ether to obtain 1.36 g of raw product which was taken up in 15 ml of 2 N hydrochloric acid. The mixture was vacuum filtered and the filtrate was adjusted to a pH of 4 with 3 ml of an aqueous molar solution of lithium acetate and then with aqueous lithium hydroxide. The mixture was vacuum filtered and the filtrate was evaporated to dryness under reduced pressure. The residue was taken up in 30 ml of ethanol with efflorescence and the mixture was vacuum filtered to obtain 515 mg of syn isomer of 3-[(1-methyl-1H-tetrazol-5-yl)-thiomethyl]-7-[2-(2-amino-4-thiazolyl)-2-(2-aminoethoxyimino)-acetamido]-ceph-3-eme-4-carboxylic acid. The mother liquors were evaporated to dryness to obtain another 133 mg of the said product and the combined products were treated again in the same manner to obtain a final yield of 430 mg of the product in the form of a white powder.

Provenance & Evidence