| 摘要 |
PURPOSE:To obtain the subject compound useful as an intermediate for producing a cephalosporin compound economically, industrially and advantageously by decarboxylating 5-(4-pyridyl)oxazole-4-carboxylic acid. CONSTITUTION:An isocyanoacetic ester of the formula, CN-CH2CO2R (R is an alkyl) is reacted with an activator of isonicotinic acid of formula I in an organic solvent in the presence of a base usually at 0-50 deg.C for several hours to several days to give 5-(4-pyridyl)oxazole-4-carboxylic acid ester of formula II. Then the compound is hydrolyzed to give 5-(4-pyridyl)oxazole-4-carboxylic acid of formula III, which is further decarboxylated by a method for heating in a solvent such as dimethylformamide in the presence of metal powder such as copper and an organic base such as pyridine at about 150-200 deg.C for 30 minutes to five hours to give the objective compound. |
