Acetyl chloride → 1,5-Dihydro-3-methyl-[1,2]diazepino[4,5,6-cd]-indol-6-one

Participants

Reaction Steps

In a manner similar to that described for compound 28, a solution of methyl indole-4-carboxylate (427 mg, 2.44 mmol) in dichloroethane (7 mL) was treated with acetyl chloride (0.5 mL) and aluminum chloride (130 mg). The intermediate ketone (198 mg, 0.92 mmol) in MeOH (5 mL) and conc. HCl (0.05 mL) was treated, as described, with hydrazine hydrate (0.1 mL). The product precipitated, was collected by filtration and rinsed with ice-cold MeOH to give 1,5-dihydro-3-methyl-[1,2]diazepino[4,5,6-cd]-indol-6-one, 168 mg (92%) as a bright yellow solid: m.p. 335-336° C.; 1H NMR (300 MHz, d6-DMSO) δ 2.17 (s, 3H), 7.19 (t, J=7.8 Hz, 1H), 7.54 (m, 2H), 7.67 (d, J=2.8 Hz, 1H), 10.12 (s, 1H), 11.90 (br s, 1H). HRMS (FAB, MH+) Calcd for C11H10N3O: 200.0824. Found: 200.0827. Anal. (C11H9N3O) C, H, N.

Provenance & Evidence