4,6-Bis[trifluoromethyl]-1,3,3-trimethyl-2-methylenepyrrolo[2,3-b]pyridine → 4,6-bis[trifluoromethyl]-1,3,3-trimethyl-6'-piperidinospiro[2H-pyrrolo[2,3-b]pyridine-2,3'-[3H]-[2H-[1,4]benzoxazino[6,5-b]benzofuran]]

Participants

Reaction Steps

A mixture of 4,6-bis[trifluoromethyl]-1,3,3-trimethyl-2-methylenepyrrolo[2,3-b]pyridine (1.83 g; 0.0059 mol) and 2-hydroxy-1-nitroso-4-piperidinodibenzofuran (2.60 g; 0.01 mol) in xylene (50 ml) was stirred and heated under nitrogen and refluxed for 24 hours. A further portion of 2-hydroxy-1-nitroso-4-piperidinodibenzofuran (1.2 g; 0.0059 mol) was added and the reaction continued for a further 24 h. The resulting dark solution was evaporated to dryness and the resulting gum chromatographed over silica (eluent: 2% diethyl ether in petroleum ether 60/80) to give 4,6-bis[trifluoromethyl]-1,3,3-trimethyl-6'-piperidinospiro[2H-pyrrolo[2,3-b]pyridine-2,3'-[3H]-[2H-[1,4]benzoxazino[6,5-b]benzofuran]] as an orange solid (0.08 g; 3%), m.pt. 195°-205° C., λmax absorbance 498 nm (polyurethane). ##STR28##

Provenance & Evidence