Process for the preparation of aminomethylene compounds

Process for preparing aminomethylene compounds of the formula ##STR10## in which R.sup.1 represents nitro, cyano, isonitrilo, COR.sup.9 CSR.sup.9, COOR.sup.9, COSR.sup.9, CON(R.sup.9 R.sup.10), SO.sub.2 R.sup.9, SO.sub.3 R.sup.9, or CONH.sub.2, or an aromatic or heteroaromatic residue which is electron-deficient at the site of preferred nucleophilic attack,

• R.sup.2 can assume the range of meaning of R.sup.1, independently of R.sup.1, and additionally represents hydrogen OR.sup.9, SR.sup.9, N(R.sup.9, R.sup.10), straight-chain or branched C.sub.1 -C.sub.8 -alkyl, C.sub.2 -C.sub.8 -alkenyl, C.sub.2 -C.sub.8 -alkoxyalkyl, C.sub.3 -C.sub.8 -alkoxyalkenyl, C.sub.3 -C.sub.8 -cycloalkyl, C.sub.6 -C.sub.12 -aryl or C.sub.7 -C.sub.10 -aralkyl, or a 5- to 8-membered, saturated or unsaturated, heterocyclic ring whose 1 or 2 heteroatoms are selected from the group comprising N, O and S,
• R.sup.3 and R.sup.4, independently of each other, represent straight-chain or branched C.sub.1 -C.sub.8 -alkyl, C.sub.2 -C.sub.8 -alkenyl, C.sub.2 -C.sub.8 -alkoxyalkyl or C.sub.3 -C.sub.8 -alkoxyalkenyl, and
• R.sup.9 and R.sup.10, independently of each other, represent straight-chain or branched C.sub.1 -C.sub.8 -alkyl, C.sub.2 -C.sub.8 -alkenyl, C.sub.2 -C.sub.8 -alkoxyalkyl, C.sub.3 -C.sub.8 -alkoxyalkenyl, C.sub.3 -C.sub.8 -cycloalkyl, C.sub.6 -C.sub.12 -aryl, or C.sub.7 -C.sub.10 -aralkyl, or a 5- to 8 -membered, saturated or unsaturated, heterocyclic ring whose 1 or 2 heteroatoms are selected from the group comprising N, O and S, where, furthermore, R.sup.9 and R.sup.10, together with the N atom which they substitute, can form a 5- to 8-membered ring which can contain a further heteroatom selected from the group comprising N, O and S,
• which is characterized in that CH-acidic compounds of the formula ##STR11## are reacted with formamide acetals of the formula ##STR12## in which R.sup.1 to R.sup.4 have the said range of meaning and
• R.sup.5 and R.sup.6, independently of R.sup.3 and R.sup.4 and independently of each other, assume the range of meaning stated for R.sup.3 and R.sup.4,
• in the presence of a secondary amine of the formula ##STR13## in which R.sup.7 and R.sup.8, independently of R.sup.3 and R.sup.4 and independently of each other, assume the range of meaning of R.sup.3 and R.sup.4,
• or in the presence of substrates which liberate such amines under the reaction conditions, at 0.degree. to 200.degree. C. with or without solvent, the molar ratio of C--H-acidic compound to formamide acetal being 1:3 to 10:1 and the quantity of secondary amine being 1 to 500 mol %, based on the formamide acetal.