Processes for preparing 3,4-dihydro 2-naphthanoic acid and 2-naphthanoic acid and esters thereof

Abstract

A process for preparing a 3,4-dihydro 2-naphthanoic acid or an ester thereof comprises heating an alpha-vinyl cinnamic acid or a (C.sub.1 -C.sub.12)alkyl, (C.sub.6 -C.sub.12)aryl, (C.sub.6 -C.sub.12)aralkyl or (C.sub.6 -C.sub.12)alkylaryl ester thereof at a temperature effective to cyclize said acid or ester thereof and obtain the corresponding 3,4-dihydro 2-naphthanoic acid or ester thereof. The alpha-vinyl cinnamic acid or ester thereof may be obtained by contacting crotonic anhydride and a benzaldehyde substituted with halo or (C.sub.1 -C.sub.12)alkyl, acyl, acyloxy, carboxy, carbalkoxy, alkylthiol or alkoxy. A process for preparing 2-naphthanoic acid or an ester thereof comprises the above steps to prepare a 3,4-dihydro-2-naphthanoic acid, and dehydrogenating said 3,4-dihydro 2-naphthanoic acid or ester thereof to obtain the 2-naphthanoic acid.

Dependencies are inferred from the claim text.