合成路线1

Romazarit (sodium salt) is prepared by a 7-step process from 4-chlorobenzoic acid, ethyl 2-chloroacetoacetate (VIII) and ethyl 2-methyl 2-hydroxypropionate (X). Reaction of the sodium salt of 4-chlorobenzoic acid (I) with ethyl 2-chloroacetoacetate (VIII) affords ethyl 3-oxo-2-(4-chlorophenylcarboxy)butyrate (II). Cyclization of (II) to ethyl 2-(4-chlorophenyl)-4-methyloxazole-5-carboxylate (III) is accomplished by treatment with formamide (IX)/sulfuric acid. Reduction of the ester (III) with lithium aluminum hydroxide in tetrahydrofuran yields 2-(4-chlorophenyl)-4-methyl-5-oxazolemethanol (IV). Chlorination of alcohol (IV) with thionyl chloride followed by reaction of crude chloromethyloxazole (V) with the sodium alkoxide derivative of ethyl 2-methyl-2-hydroxypropionate (X) yields ethyl [2-[(4-chlorophenyl)-4-methyl-5-oxazolyl]methoxy]-2-methylpropionate (VI). Hydrolysis of the ester (VI), acidification and recrystallization affords Ro 31-3948 (VII) as a white solid, which is converted to the sodium salt by treatment with sodium isopropoxide in isopropanol.