| abstract |
(A)2-Nitrobenzylideneamine cpds. of formula (Ia) and trimers of formula (Ib) are new, where R=H or a gp. of formula R1 or R2. - Prodn. of dimethyl 1,4-dihydro-2,6-dimethyl-4 -(2-nitrophenyl)-3,5 -pyridinedicarboxylate of formula (II) is effected by (a) reacting (Ia) or (Ib) with methyl acetoacetate (III) in an inert solvent, opt. in the presence of methyl 3-aminocrotonate (IV), NH4X (X= 1-5C alkanoate, 1/2 CO3 2-, HCO3- or OH-) or NH3; or (b) reacting 2-nitrobenzaldehyde (V) with aq. NH4OH at 101-120 deg.C and 2-6 bar. |