Hydrochloric Acid → HCID 131713216, compound

Participants

Reaction Steps

61 ml of a 0.18 M HCl solution in CH2Cl2 (1.1 mol equivalent, prepared by introducing dry gaseous hydrogen chloride into dry CH2Cl2) are added to a solution, cooled to 0°, of 4.97 g of 7β-[2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid pivaloyloxymethyl ester (free base) in 50 ml of CH2Cl2. After stirring for 10 minutes, diethyl ether is added to the solution and a precipitate forms. The mixture is stirred for a further 1/2 hour at 0°, the precipitate is filtered off, washed with diethyl ether and dried in a high vacuum at 30°. The crude hydrochloride is obtained as a pale beige powder which is dissolved in approximately 50 ml of CH2Cl2, concentrated slightly and left to stand overnight at approximately 5°. The compound that has crystallised out is filtered off, washed with a little CH2Cl2 and diethyl ether and dried as described above. The colourless 7β-[2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid pivaloyloxymethyl ester hydrochloride having a melting point of 187°-191° is obtained in syn-form.

Provenance & Evidence