The synthesis of a dipyrido[3,2-b:3′,4′-e][1,4]diazepinone: Convenient access to a C-ring isomer of the HIV-1 reverse transcriptase inhibitor nevirapine

The synthesis of 11-ethyl-5-methyldipyrido[3,2-b:3′,4′-e][1,4]diazepin-6-one 6, the first representative of a C-ring dipyridodiazepinone isomer of the HIV-1 reverse transcriptase inhibitor nevirapine 1 is described. The key step involves the regiospecific lithiation of 3-(tbutoxycarbonylamino)pyridine 7 followed by trapping with N-(2-chloropyridyl)-N-methylcarbamoyl chloride 10.