| 摘要 |
<p>NEW MATERIAL:1-(2-Amino-4-thiazolyl)propene-1,3-dicarboxylic acid half ester of formula IV (R is ester-forming group; R<1> and R<2> are H or amino-protecting group). USE:Agent for modifying the amide side chain of penicillin and cephalosporin or the amino group of an arylglycine-type penicillin and cephalosporin, or synthetic raw material for excellent antibiotic substances. PREPARATION:Objective compound of formula VI can be prepared by (1) reacting the haloacetylmalonic acid ester of formula I (Hal is halogen) with thiourea to obtain the compound of formula II, (2) protecting the amino group of the compound, (3) reacting the resultant compound of formula III with a haloalkenoic acid ester, (4) hydrolyzing and decarbonating the obtained compound of formula IV(R<3> is H or COOR) or its protected derivative to the compound of formula V, and (5) reacting the product with a halfesterifying agent and an alcohol. All of the compounds of formulas II, III, IV and V are novel.</p> |
