Propargyl alcohol → 5,11-Dihydro-11-[[(2-propynyl)oxy]carbonyl]-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one

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Reaction Steps

At 15° to 20° C., 3.08 g (0.048 mol) of n-butyl-lithium in 30 ml of n-hexane are added dropwise to a solution of 2.24 g (0.04 mol) of propargyl alcohol in 120 ml of tetrahydrofuran. After it has all been added, the mixture is stirred for a further 30 minutes at ambient temperature and then mixed with a suspension of 10.9 g (0.04 mol) of 11-chlorocarbonyl-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one in 250 ml of tetrahydrofuran. In order to complete the reaction the mixture is stirred for a further hour. It is evaporated to dryness in vacuo and the residue is crystallised by stirring in water. After recrystallisation from ethyl acetate, 7.5 g (64% of theory) of the desired product are obtained, m.p. 213° C.

Provenance & Evidence