Patent ID: 6369271
Filing Date: 2002-04-09
Classification: C07C

Abstract:
A process for preparing a compound of the formula (I) wherein:R1 and R2, which are identical or different, are each hydrogen; C1-C6-alkyl optionally substituted by halogen; C1-C6-alkoxy; C1-C6-acyl; C1-C6-alkoxycarbonyl; COOH; phenyl; benzyl; halogen; hydroxy; nitro; or amino, or R1 and R2 together with adjacent carbon atoms of the phenyl ring form a saturated or unsaturated 5- or 6-membered carbocyclic group optionally substituted by C1-C4-alkyl, halogen, COOH, phenyl, or hydroxy groups, the process comprising: saponifying with hydrochloric acid at elevated temperature under pressure, in the presence of an organic solvent selected from an aliphatic or aromatic hydrocarbon or an aromatic chlorohydrocarbon with 6-10 carbon atoms, a compound of the formula (IV) wherein:R1 and R2 are as hereinbefore defined in this claim, and ROx is an oxazolin-2-yl group optionally mono-, di-, tri- or tetra-substituted by groups selected from C1-C6-alkyl group optionally substituted by halogen, hydroxy or C1-C4-alkoxy; C1-C6-alkoxy; phenyl optionally substituted by C1-C4-alkyl, C1-C4-alkoxy, hydroxy, nitro, or amino; benzyl; pyridyl; or C1-C6-alkoxycarbonyl.