| 摘要 |
<p>1. Process for the preparation of unsymmetrical 1,4-dihydropyridines of the formula I see diagramm : EP0124743,P4,F1 in which R represents a phenyl radical which is optionally mono- or disubstituted by nitro and/or chlorine and R1 represents a C1 -C4 -alkyl radical which is optionally substituted by a C1 -C4 -alkoxy group, and R2 represents a C1 -C12 -alkyl radical which is optionally substituted by a C1 -C4 -alkoxy group, a trifluoromethyl group or the radical [C6 H5 CH2 ] [CH3 ]N, the radicals R1 and R2 not being identical, by reaction of an ylidene compound of the formulae II or III see diagramm : EP0124743,P4,F2 see diagramm : EP0124743,P4,F3 with an enamine compound of the formulae IV or V see diagramm : EP0124743,P4,F4 see diagramm : EP0124743,P4,F5 characterized in that the ylidene compound of the formulae II or III is prepared by reaction of a ketocarboxylic ester of the formulae VI or VII see diagramm : EP0124743,P4,F6 see diagramm : EP0124743,P4,F7 with an aldehyde of the formula RCHO, in an organic solvent (lower aliphatic alcohol), in the presence of catalytic amounts of piperidine acetate, at temperatures from - 10 degrees C up to 100 degrees C.</p> |
