| abstract |
New compounds of the formula: in which R1, R2, R4 and X have the meanings given in Claim 1 can be used for the pre-emergence or post-emergence control of monocotyledon and dicotyledon plant species and for inhibiting the enzyme phosphodiesterase in humans and other mammals. Some of the compounds of the formula I are prepared from new compounds of the formula: in which R, R1, R2 and X have the meanings given in Claim 6 by heating in a nonpolar solvent followed optionally by chlorination or bromination. The compounds of the formula II in which R, R1, R2 have the meanings given in Claim 8 and X represents oxygen or sulphur are obtained by condensation of a 4-imidazolecarboxaldehyde of the formula: with a compound of the formula: H2N-NH-CX2R.h |