PROCESS OF PREPARING BENZOPYRAN-5-OLS AND COUMARIN INTERMEDIATES THEREFOR VIA NEW beta-KETO ESTERS.

摘要

1307646 5-Hydroxycoumarin derivatives BEECHAM GROUP Ltd 5 Oct 1970 [31 Oct 1969] 47170/70 Haading C2C The invention comprises compounds of formula and their salts and ethers, wherein R 2 is a C 1-12 aliphatic group and R 4 is an organic group (e.g. R 2 = pentyl R 4 =Ph). These compounds are prepared by reacting in presence of an acid, a 1 - R 4 CO - 4 - R 7 O 2 CCH 2 CO-piperidine (R 7 = C 1-6 alkyl but not Me 3 C) with a 5-R 2 -resorcinol or a monoether or acyl derivative thereof. As starting, material, there is prepared ethyl tert.- butyl N-benzoylisonipecotinylmalonate.