Improvements in or relating to the preparation of 7-oxobenzonorbornene derivatives

摘要

The invention relates to a 7-methylenebenzonorborna-2,5-diene compound of the general formula in which R is hydrogen or alkyl group having not more than 5 carbon atoms, R1 and R11 are each an alkyl group having not more than five carbon atoms, an aryl group or aralkyl group having not more than fifteen carbon atoms and to the corresponding 7-methylenebenzonorbornene compounds of the general formula Compounds claimed per se are 7-isopropylidenebenzonorborna - 2,5 - diene and 7 - isopropylidenebenzonorbornene. The compounds may be prepared by reacting a 1,2-dihalogenobenzene compound of the general formula in which R is H or alkyl group having not more than five carbon atoms and X and Y are each a halogen atom with a fulvene compound of the general formula in which R1 and R11 are each an alkyl group having not more than five carbon atoms, an aryl group or an aralkyl group having not more than fifteen carbon atoms in the presence of dehalogenating agent to give the diene compound of Formula 3 which is hydrogenated to give a benzonorbornene compound of Formula 4.ALSO:The invention relates to the process for preparing 7-oxobenzonorbornene derivatives comprising reacting a 1,2-dihalogenobenzene compound of the general formula in which R is a hydrogen atom, an alkyl group having not more than five carbon atoms, an alkoxy group having not more than five carbon atoms or a halogen atom and X and Y are each a halogen atom, with a fulvene compound of the general formula in which R1 and R11 are each an alkyl group having not more than five carbon atoms, an aryl group or an aralkyl group having not more than fifteen carbon atoms in the presence of a dehalogenating agent to give a 7-methylenebenzonoborna-2,5-diene compound of the general formula hydrogenating the latter with one mol equivalent of hydrogen to saturate the double bond at the 2-position and oxidizing the resultant 7-methylenebenzonorborn compound of the general formula to give a 7-oxobenzonorbornene compound of the general formula The invention also relates to compounds of the general formulae (III) and (VI) above. Compounds claimed per se are 41-fluoro-7-isopropylidenebenzonorbornene 41 - methoxy-7-isopropylidenebenzonorbornene, 41 - chloro - 7 - isopropylidenebenzonorbornene, 41 - methyl-7-isopropylidenebenzonorbornene and the corresponding 2,5-diene compounds.