Isopropanol → 2,3-Dihydro-4-methyl-2-[2-(4-morpholinyl)ethyl]-pyrido[3,2-f][1,4]oxazepin-5(4H)-one maleate

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Reaction Steps

2-(2-Chloroethyl)-2,3-dihydro-4-methylpyrido[3,2-f][1,4]oxazepin-5(4H)-one hydrochloride, 16 g (0.58 mole) was dissolved in morpholine (30 ml) and stirred overnight at room temperature. To the solution was added dilute sodium hydroxide solution (50 ml) and the resulting mixture extracted with chloroform (3×30 ml). The chloroform was removed on the rotary evaporator with aspiration. The residual morpholine was removed in vacuo at 50° C. (rotary evaporator). To the residual free base (15.5 g, 0.053 mole) was added isopropyl alcohol (1 liter) and maleic acid (9.24 g g, 0.080 mole). The mixture was heated to boiling and the clear solution cooled at 20° C. for several hours. The resulting crystals, 16 g (68.1%), were recrystallized from isopropyl alcohol, m.p. 163°-165° C.

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