Thermal rearrangements of 3,5-diphenylisoxazole

Abstract

Flash pyrolysis of 3,5-diphenylisoxazole at 960 °C yields 2,5-diphenyloxazole, 2-phenylindole, and benzamide as major products. 2,3-Diphenyl-2H-azirine and fluorene were minor products. A similar experiment with 3,5-diphenyl[3,5-¹³C₂]isoxazole produces 2,5-diphenyl[2,5-¹³C₂]oxazole, 2-phenyl[2-¹³C]indole, 2,3-diphenyl-2H-[¹³C]azirine, and [9-¹³C]fluorene. The thermal, photochemical, and electron-impact behaviour of 3,5-diphenylisoxazole are seen to be related.