Ammonium nitrate → 2-(3-Amino-2,4-dioxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl)-N-isopropyl-N-(4-methoxy-phenyl)-acetamide

Participants

Reaction Steps

To a stirred solution of 2-[3-Amino-5-(4-methoxybenzyl)-2,4-dioxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl]-N-isopropyl-N-(4-methoxyphenyl)-acetamide (2.63 g, 5.09 mmol) in acetonitrile/H2O (9:1, 70 mL) at ambient temperature was added cerric ammonium nitrate (10.05 g, 18.3 mmol) portionwise over one hour. The solution was stirred overnight at room temperature. The solution was concentrated in vacuo, chased with toluene (2×50 mL) and the residue was extracted with CH2Cl2 (3×50 mL), filtered and concentated to an orange glass. The crude product was purified by flash chromatography on silica gel (100 g) eluting successively with CH2 Cl2 /CH3OH (15:1, 1.5 L) and CH2Cl2 /CH3OH (10:1, 1.3 L). Appropriate fractions were combined and concentrated under reduced pressure to give the title compound (1.97 g, 4.97 mmol) as a brown foam: 1H NMR (300 MHz, DMSO-d6): d 10.68 (br s, 1H), 7.39-6.98 (m, 8H), 5.75 (s, 1H), 4.76 (m, 1H), 4.16-3.92 (m, 4H), 3.7 (s, 3H), 3.15 (m, 2H), 0.97 (m, 6H); TLC (CH2Cl2 /CH3OH (13:1)): Rf =0.21.

Provenance & Evidence