Purificn. of 7-amino-3-((z)-1-propen-1-yl)-3 -cephem-4-carboxylic acid - useful in prodn. of broadband antibiotics

摘要

Depletion of 7-amine-3- (E)-1-propen-1-yl) -3-cephem- 4-carboxylic acid (Ia) in mixts. of (Ia) and the corresp. z-isomer (Ib) comprises: (a) forming the hydrochloride salt of the cpd. (I) (in which the propenyl gp. has Z- or E-configuration) form (I) and HCl in a solvent (mixt) in which (Ia) and (Ib) have different solubilities, and opt. converting the salt to (I) with reduced amts. of (Ia) by adjusting the pH; (b) solubilising at least part of (Ia) in mixts. of (Ia) and (Ib) (as the salt), in a solvent (mixt) in which (Ia) and (Ib) have different solubilities, followed by opt. conversion of the salt into (I) with reduced amts. of (Ia), by adjusting the pH; (c) forming a salt of formula (I') by reacting (I) with a Li-, Na- or K- or an amine of formula (IV), in a solvent (mixt) in which Hg Z- and E-isomers of the salt have different solubilities, precipitating the salt, opt. by adding a counter solvent, and converting (I') to (I) (with reduced amt. of (Ia)), or the HCl salt of (I) by adding acid; (d) dissolving (I) in a solvent (mixt) iwth a Li, Na- or K- base or ammonia, precipitating (I') by adding a Li-, Na-, or K-sources or an amine of formula (IV) and opt. a counter solvent, and converting (I') into (I) (with reduced amts. of (Ia), or the HCl salt of (I), by adding acid; or (e) subjecting a soln. of (I) to absorption chromatography. m = H (in I) or X (in I'); X = Li, Na, K or NHR1R2R3; R1-R3 = H, 1-8C alkyl, 4-8C cycloalkyl or opt. substd. benzyl; NR1R2 = a 5-6 membered heterocycle which opt. contains 1-2 additional heteroatoms.