Substituted 1,3,4,9-tetrahydropyrano [3,4-b]indole-1-acetic acids.

摘要

A novel process is described for the production of substituted 1,3,4,9-tetrahydropyrano[3,4-b-]indole-1-acetic acids having useful analgesic and anti-inflammatory activity and having the formula (I) <CHEM> wherein R<1> is lower alkyl, R<4> and R<5> are hydrogen, lower alkyl or halogen and R<2> is hydrogen, 4-halogen 2,4-dihalo, 3-trifluoromethyl or 4-methoxy via the intermediate of formula <CHEM> v