摘要:
Process for the preparation of substituted 3-amino-2-(benzoyl)-acrylic acid esters of the formula I ##STR1## in which R.sub.1 denotes an alkyl radical with 1 to 4 C atoms, X.sub.1 denotes halogen, in particular fluorine or chlorine, X.sub.2, X.sub.3, X.sub.4 and X.sub.5 denote hydrogen, halogen, in particular fluorine or chlorine, an alkyl radical having 1-4 C atoms or an alkoxy radical having 1-4 C atoms in the alkyl chain, by selectively reducing a substituted 2-cyano-3-hydroxy-3(phenyl)acrylic acid ester of the formula II ##STR2## in which R.sub.1, X.sub.1, X.sub.2, X.sub.3, X.sub.4 and X.sub.5 have the meaning given above, and a process for the preparation of intermediate products for antibacterially active compounds from these compounds.
摘要:
Process for the preparation of allantoin in a two-stage reaction by reaction of methyl glyoxylate methyl hemiacetal with urea in the presence of an inorganic acid at a pH-value of 1.0-2.0 and carrying out the ring-closure reaction at a pH-value of 7.0 to 9.0 in a second reaction stage.
摘要:
Process for the preparation of 5-arylhydantoins by reaction of an allantoin acid alkyl ester with an aryl compound in a concentrated inorganic acid at temperatures from room temperature to 150.degree. C., with or without a phase transfer agent.