Process for the preparation of styryl compounds

Preparation of styryl compounds involves reaction of a phenylamine with either a mixture of a trialkyl ortho-formate and a methylene-active cyano compound or an acrylic compound. Preparation of styryl compounds of formula (I) involves reaction of a phenylamine of formula (II) with either: (i) a mixture of a trialkyl ortho-formate of formula (III) and a methylene-active cyano compound of formula CH2(Z')-CN (IV); or (ii) an acrylic compound of formula (V). R1 and R2 = (a) 1-12C alkyl optionally substituted by halogen such as F, Cl or Br, -OH, -CN, -OR5, -SR5, -O-C(O)-R5, -C(O)-R5, -C(O)-OR5, -NR6R7 or -NH-CH2-R5; or (b) an optionally substituted alkoxylate of formula -(-CH2CH2-O-)n-R; (c) R1 = a group of formula CH2(Z')-CN (VI) where (R)', (R3)', (R4)' and (Z)' = as for R1, R3, R4 and Z (see below); or (d) R1 and R2 together form a 4-6C alkylene group; R = H or optionally substituted phenyl, the substituents especially being halogen (especially F or Cl) or 1-8C alkyl or alkoxy; n = 1-50 (especially 1-20); or R5 = 1-12C alkyl or 6-10C aryl (especially phenyl or naphthyl), the aryl groups optionally being substituted by halogen such as F, Cl or Br, alkyl, carbonyl or carboxylic acid ester; R6 and R7 = optionally substituted aryl or alkyl; R3 and R4 = H, 1-6C alkyl, trifluoromethyl, 1-4C alkoxy, phenoxy or halogen such as F, Cl or Br; Z' = -CN, -SO2X, -C(O)X1, -C(O)OX2 or -C(O)NY1Y2; and X, X1, X2, Y1 and Y2 = 1-6C alkyl, 5-7C cycloalkyl, 1-3C alkylphenyl or optionally substituted phenyl or naphthyl, with Y1 and Y2 optionally also forming a 5-7-membered ring with the N atom to which they are bonded.