| 摘要 |
<p>The present invention relates to a process for preparing 2alpha-methyl-2beta-substituted methyl penam derivatives from cepham derivatives, more particularly the present invention provides a novel process for preparing 2beta-heterocyclyl methyl penam derivatives of the formula (I) by reacting a cepham compound with a heterocylic amine to form an intermediate compound, and oxidizing the intermediate compound to produce the 2beta-heterocyclyl methyl penam derivatives of the formula (I), wherein R<SUB>1 </SUB>represents carboxylic acid protecting group; R<SUB>2 </SUB>and R<SUB>3 </SUB>may be same or different and independently represent hydrogen, halogen, NH<SUB>2</SUB>, acylamino, phthalimido with a proviso that both R<SUB>2 </SUB>and R<SUB>3 </SUB>are not NH<SUB>2</SUB>, acylamino, phthalimido; Het represents a 5 or 6 membered nitrogen containing heterocycle ring system having one or more heteroatoms selected from O, S, or N.</p> |
