Triethylamine → Cyclopentanecarboxylic acid (2,4-Dioxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazapin-3-yl)-amide

Participants

Reaction Steps

Combine 3-amino-1H-1,5-benzodiazepine-2,4-(3H, 5H)-dione (7.0 g, 36.6 mmol) and triethyl amine (4.07 g, 40.3 mmol) in 120 mL DMF and add dropwise cyclopentanecarbonyl chloride (5.34 g, 40.3 mmol) at RT. After stirring overnight, remove DMF under reduced pressure, suspend the residue in a mixed solvent (CHCl3/i-PrOH=3/1, 400 mL). Collect an off-white solid via suction filtration to give the title compound. Wash the filtrate with NaHCO3 (sat.2×100 mL) and dry with Na2SO4. Concentrate the the solvent to give second crop of title compound, total 9.13 g, yield 87%: 1H NMR (300 MHz, DMSO-d6): 10.70 (s, 2H), 8.11 (d, 1H, J=7.8 Hz), 7.24–7.15 (m, 4H), 4.73 (d, 1H, J=7.5 Hz), 2.96–2.87 (m, 1H), 1.74–1.45 (m, 8H).

Provenance & Evidence