Synthesis of Formylphenyl 1-Oxo-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole-7-carboxylates and Their (E)-1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-yliminomethyl Derivatives

Formylphenyloxohydroepoxyisoindole carboxylates were prepared by the reaction of 4-hydroxy-3-methoxy-, 4-hydroxy-3-ethoxy- and 3-hydroxy-4-methoxybenzaldehydes with substituted isoindolecarboxylic acids {2-methyl-1-oxo-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole-7-carboxylic, 2-(3,4-dimethoxyphenethyl)1-oxo-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole-7-carboxylic, 2-(benzo[d][1,3]dioxol-5-ylmethyl)-1-oxo1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole-7-carboxylic, 6-oxo-3,4,6,6a,7,8-hexahydro-2H,10bH-8,10a-epoxy[1,3]oxazino[2,3-a]isoindole-7-carboxylic, 2-(2,3-dichlorobenzyl)-1-oxo-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole-7-carboxylic} in dichloromethane in the presence of dicyclohexylcarbodiimide. The corresponding (E)-azomethines were synthesized by condensation of formylphenyloxohydroepoxyisoindole carboxylates with 4-amino-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one in methanol.