3-Unsatd. hydrocarbyl 3-cephem 4-carboxylic acids prepn. - by treating 3-triflyl cpd. with hydrocarbyl tri:alkyl stannane in presence of palladium cpd. and phosphine

摘要

Prepn. of 3-hydrocarbyl-3- cephem-4-carboxylic acids of formula (I) or their salts or esters comprises: (i) providing a 3-trifjluromethane su,lsulphonloxy-3-cephem (II) starting cpd. in a relatively polar aprotic solvent; (ii) contacting this with an at least equimolar amt. of R1-trialkyl stannane (III) in presence of 1-10 mole% of a Pd(O) or Pd (II) cpd. and 3-30 mole.% of tri(2-furyl)phosphine at 25-65 deg.C, protected from atmos.oxygen, for 1-75 hrs; and (iii) recovering (I) from the reaction mixt. R1 = opt. substd., 1-alkyl, opt. conjugated 1-polyalkenyl, 1-alkynyl, phenyl, Het or Het-CH2; Het = 2-, 3- or 4-pyridyl, 2-iomidazolyl, 2-thiazolyl, 2- or 3- furyl, 2-pyrryl 2-thienyl; Q = H, t-butoxycarbonyl, a silyl protecting gp.; or the acyl gp. of a known 7-acylamino cephalosprin antibiotic; aryl and heteroaryl gps. may be substd. by 1-3 alkyl, OH, alkoxy, halo, amino,alkylamino, dialkylamino, NO2, COOH, alkoxycarbonyl and CN gps.