Cyclohexane 1,3 dione derivative and its production manner

摘要

PROBLEM TO BE SOLVED: To obtain the subject new compound having a strong herbicidal activity and useful as a starting raw material for a new cyclohexane-1,3-dione derivative used as a selective herbicide. ;SOLUTION: A cyclohexane-1,3-dione derivative of formula I [X is H, a 1-6C alkyl, etc.; (X)_n is the number of substituents X on the benzene ring; (n) is 1-3; R¹ is H, a 1-4C alkyl], e.g. 5-(2,3-dihydro-2,2,4,5,6-pentamethylbenzofuran-7- yl)cyclohexene-1,3-dione. The compound of formula I is obtained by reacting a benzalacetone of formula II with a maleate ester in the presence of an alkali metal methoxide at the boiling point of methanol and subsequently decarboxylating the obtained compound of formula III (M is an alkali metal or an alkaline earth metal).;COPYRIGHT: (C)1998,JPO