Pyridine → 3H-1,5-Benzodiazepine, 2,4-bis(4-methyl-1-piperazinyl)-3-propylidene-

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1-[2,4-bis(4-methyl-1-piperazinyl)-3H-[1,5]benzodiazepin-3-yl]-1-propanol (1.195 g, 3 mmol), triethylamine (2.50 ml, 18 mmol) and pyridine (0.024 ml, 0.3 mmol) in tetrahydrofuran (10 ml) under constant flow of argon, at 0° C., a solution of trifluoroacetic anhydride (1.26 ml, 9 mmol) in tetrahydrofuran (5 ml) was added dropwise. The reaction mixture was stirred for another hour at 0° C. Methanol (5 ml) was added. The solution was allowed to warm to 10° C., while strongly agitated NaOH (1 M, 20 ml) was added dropwise. Dichloromethane (30 ml) was added and the phases were separated. The organic phase was dried over anhydrous Na2SO4 and the solvent was evaporated at reduced pressure. The crude product was suspended in isopropyl ether (8 ml) and filtered off. The filtrate was evaporated at reduced pressure to give 0.971 g (84%) of the title compound as a yellow resin. The product obtained was characterized using 1H-NMR spectroscopy and was found to be identical to the product obtained by method A.

Provenance & Evidence