A MULTISTEP PHOTOREACTION OF AROMATIC-ALDEHYDES WITH HETEROAROMATICS IN THE SOLID-STATE

Mixed crystals, prepared by resolidification of the melt of a mixture of 5-formyl-1,3-dimethyluracil (1a) and antipyrine (7) crystals (molar ratio, 1:2.5), and irradiated with a high-pressure mercury lamp under nitrogen, gave a photocondensation product ga, as in the previously r eported solid state photoreaction between 1a and indole. Similarly, ir radiation of mixed crystals of substituted benzaldehydes and indole ga ve the corresponding photocondensation product 3. A mechanism involvin g an oxetane intermediate 4 was proposed for the formation of 3. The n ature of the starting mixed crystals was examined by powder X-ray diff ractometry.