| abstract |
A compound of formula I ** (Formula) ** wherein X is O, S, N-CH3, CH = CH or CAlk = CAlk where the Alk are independently C1-4 alkyl; R1 and R2 are independently hydrogen, halogen, C1-4 alkyl, C1-4 alkoxy or trifluoromethyl; and Het is a radical having one of the following formulas (a) to (p): ** (Formulas) ** wherein R3 and R8 are independently hydrogen or C1-4 alkyl; R4 is hydrogen, halogen, C1-4 alkyl, cyano, nitro, formyl or (C1-4) alkylcarbonyl; R5 and R6 are independently hydrogen, C1-7 alkyl, C3-7 alkenyl, C3-7 cycloalkyl, C3-7 cycloalkyl C1-4 alkyl, (C1-4 alkoxy) C2-5 alkyl or benzyl; R7 is hydrogen, hydroxy, C1-4 alkyl or C1-4 alkoxy; W is N, C-CN, C-NO2, C-COH or C-CO-Alk where Alk is defined as above; and X is defined as above; in the form of the free base or an acid addition salt. |