Dimethylformamide → 2-((E)-2-(dimethylamino)vinyl)-1-methyl-5-nitro-1H-indole-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

5-nitro-2-methyl-1H-indole-3-carbaldehyde (200 mg, 0.98 mmol) was dissolved in 5 mL dry DMF, followed by the addition of N,N-dimethylformamide dimethyl acetal (467 mg, 521 □L, 3.92 mmol). The reaction mixture was heated to 100° C. for 2 h and turned from light yellow to dark red over the course of the reaction. The crude reaction was concentrated in vacuo to obtain a red solid. The crude solid was washed with 5:1 EtOAc/hexane (6×10 mL), followed by hexane (2×10 mL) to obtain 2-((E)-2-(dimethylamino)vinyl)-1-methyl-5-nitro-1H-indole-3-carbaldehyde as a brick red solid (215 mg, 85% yield). Mass and purity were confirmed by LC/MS using an acetonitrile gradient with 5 mM ammonium formate pH 6.5. Theoretical (M+H)+ m/z for C14H15N3O3=273.11; Found 274.00. 1H NMR (400 mHz, DMSO-d6) δ 9.80 (s, 1H), 8.03 (dd, J=8.9, 2.4 Hz, 1H), 7.58 (d, J=9.0 Hz, 1H), 7.58 (m, 2H), 5.25 (d, J=13.0 Hz, 1H), 3.72 (s, 3H), 3.03 (s, 6H).

Provenance & Evidence