| 摘要 |
<p>NEW MATERIAL:The compound of formula I [X is halogen or H; R is amino acid residue (ester bond) which may be substituted with protecting group]. EXAMPLE:4-Bromomethyl-5-t-butoxycarbonyl-L-alanyloxymethyl-1, 3-dioxolen-2- one. USE:Useful as a raw material of prodrugs of penicillin, cephalosporin, and other drugs. PROCESS:The compound of formula I can be prepared by reacting the compound of formula II (X' is halogen) with the compound of formula HO-R in an inert organic solvent such as acetone, dioxane, etc. at -20-0 deg.C. The compound of formula HO-R is used preferably in the form of salt (e.g. sodium salt, calcium salt, etc.). When the compound of formula HO-R is used in the form of free carboxylic acid, the reaction is carried out in the presence of an acid acceptor such as potassium acetate, pyridine, etc.</p> |
