2,6-Dimethyl-4-(trimethyl-stannyl)pyridine → ethyl (S)-10-(2,6-dimethyl-4-pyridinyl)-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 19.35 g ethyl (S)-10-bromo-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate, 16.20 g 2,6-dimethyl-4-(trimethylstannyl)pyridine, 0.88 g dichlorobis(triphenylphosphine)palladium in 200 ml ethanol was placed in a stainless steel Parr apparatus and the system flushed with nitrogen and pressurized to about 80 psi with nitrogen. The system was heated at 150° C. for 4 hours. The reaction mixture was cooled and concentrated in vacuo, and the residue was taken up in chloroform, filtered and chromatographed on silica gel using 5% methanol in chloroform to give 14.90 g ethyl (S)-10-(2,6-dimethyl-4-pyridinyl)-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate.

Provenance & Evidence