Oxalic Acid → 7-Chloro-2,3-dihydro-4-methyl-2-[2-methyl(phenylmethyl)amino]pyrido[3,2-f][1,4]oxazepin-5(4H)-one oxalate

Participants

Reaction Steps

To a solution of 6.0 g (0.022 mole) of 7-chloro-2-(2-chloroethyl)-2,3-dihydro-4-methylpyrido[3,2-f][1,4]oxazepine-5(4H)-one in 50 ml of absolute ethanol was added 5.3 g (0.044 mole) of benzylmethylamine and the mixture heated to reflux for three days. The solvent was removed by rotary evaporation, and the residue was taken up in 100 ml of methylene chloride, which was subsequently washed with 2×50 ml of dilute sodium hydroxide and 50 ml water, dried over sodium sulfate, filtered, and concentrated by rotary evaporation. Residual benzylmethylamine was removed at 95° C., 0.5 mm Hg. However, the mass spectrum now showed starting material; therefore, the residue was taken up in 50 ml of absolute ethanol. To the resulting solution was added 2.7 g (0.022 mole) of benzylmethylamine and the mixture heated to reflux for 24 hrs. The reaction mixture was subjected to the same work-up as mentioned before. The syrup was treated with oxalic acid in isopropyl alcohol. The resulting crystals were recrystallized from ethanol/isopropyl alcohol to give 4.7 g (47.9%) of white crystals, m.p. 176°-179° C.

Provenance & Evidence