| 摘要 |
<p>Disclosed herein are novel thiazoline azetidinone vinyl halides are of the formula I wherein X is Cl or Br; R is hydrogen or a carboxylic acid protecting group; and R5 is (a) hydrogen, C1-C4 alkyl or halo(C1-C4)alkyl; (b) a group R6 wherein R6 is phenyl which is either unsubstituted or is substituted by 1 or 2 groups selected from the following: fluoro, chloro, bromo, iodo, nitro, cyano, C1-C4alkyl, C1-C4alkoxy, protected hydroxy, carbonyl, trifluoromethyl and methanesulfonamido; (c) a group of the formula R6(O)mCH2 wherein m is 1 or 0 and R6 is as defined above; (d) a group of the formula R6a CH2 wherein R6a is cyclohexadienyl, 2-furyl, 2-thienyl, ox 3-thienyl; or (e) a group of the formula COOR wherein R is as defined above. They are prepared by reacting compounds of the formula II wherein R and R5 are as previously defined, with from about 1.0 to about 1.3 equivalents of a halogenating compound of the formula F?X2 IV wherein Z is hydrogen, halo, C1-C4alkyl or C1-C4alkoxy, and X is Cl or Br. The aforesaid novel thiazoline azetidinone vinyl halides are useful in the preparation of certain cephalosporin antibiotics.</p> |
