6-phenyl:thio, 6-imidazolyl salicylic acid alkyl ester derivs. - intermediates in prepn. of herbicides and bio:regulators via cheaper synthetic pathway

摘要

Substd. salicylic acid alkyl ester derivs. of formula (I) are new. R1 = 1-6C alkyl; R2 = H or 1-4C alkyl; R3 = N-bonded imidazolyl or triazolyl, each opt. substd. on the C atoms with 1-3 gps. chosen from 1-4C alkyl, 1-4C alkylthio, halogen or Ph, or R3 is an opt. mono, di or tri-substd. (or mono to penta-halo substd.) phenyl thio gp. of formula (i). R4-R8 = H, halogen, CN, NO2, 3-6C alkenyl, 3-6C alkenyloxy, 3-6C alkynyloxy, 3-6C alkynyloxy (these last 4 gps. opt. substd. by 1-5 halogen atoms), di-(1-4C)alkylamino, 3-8C cycloalkyl (opt. substd. by 1-3 1-4C alkyl gps.), 1-10C alkoxycarbonyl, 1-4C alkylthio, PhO (opt. substd. by 1-5 halogen atoms and/or 1-3 of the following 1-4C alkyl, 1-4C haloalkyl, 1-4C haloalkoxy, 1-4C alkoxy or 1-4C alkylthio), 1-10C alkyl or 1-10C alkoxy (these last 2 opt. substd. by 1-5 halogen atoms and/or one of the following: 1-4C alkoxy, 1-4C alkylthio, Ph or PhO (these last 2 themselves opt. substd. by 1-5 halogen atoms and/or 1-3 of the following gps. 1-4C alkyl, 1-4C haloalkyl, 1-4C haloalkoxy or 1-4C alkylthio)). USE/ADVANTAGE - (I) are intermediates in the prepn. of salicylic acid derivs. with herbicidal and/or bioregulating properties. (I) provide a cheaper route for the synthesis of these biologically active cpds., in that the starting materials 2-chloro-3-alkoxy-carbonyl -2,4-hexadiene-carboxylic acid esters (II) for the prepn. of (I) are readily available. The need to use the expensive starting material 2-fluoro-6-methoxy benzonitrile is avoided.