| 主权项 |
1. A process for preparing carboxylic acids of the formula XII or XIIA: the process comprising: a) reacting a carbonyl compound of formula XIII with a base and a C1-C3 alkylating agent, in a suitable solvent, to provide a compound of formula XIV: b) reacting the compound of formula XIV with ozone, in a suitable solvent, followed by reaction with a dehydrating agent in the presence a base to provide an ester of formula XV; c) hydrolyzing the ester of formula XV, in a suitable solvent, in the presence of a suitable base, to provide an acid of formula XII: d) optionally resolving the racemic acid of formula XII to provide the enantiomers XIIA and XIIA′ d′) Alternatively, the acid XII obtained in step c) may be reacted with an organic base, such as a primary or secondary amine, in a suitable solvent, to provide the corresponding salt of formula XVI wherein: R in step a) is a C1-3 alkyl provided by the C1-C3 alkylating agent; R1 and R2 are each independently hydrogen, C1-7 alkyl or C3-10 carbocycle, with the proviso that both R1 and R2 are not hydrogen; R4 is hydrogen, C1-3 alkyl, halogen or nitrile; and X is halogen; B in step d′) is a primary or secondary amine. |
