3-(2-dimethylamino-ethyl)-1H-indole-5-carbaldehyde → HCID 68472493, compound

Participants

Reaction Steps

A 100 ml flask is charged with 3-(2-dimethylamino-ethyl)-1H-indole-5-carbaldehyde (Reference Example 9; 2.16 g, 10 mmol), methanol (50 ml), and hydrazinecarboxylic acid isobutyl ester (1.32 g, 10 mmol). This mixture is heated at reflux, and after 6 hours the conversion is 70% by NMR. Heating is continued over night, and removal of the solvent gives the crude product, which is then filtered over a pad of silica (40 g) with the following eluent: CH2Cl2:methanol: NEt3 90:10:1 (v:v:v), ca. 700 ml. Removal of the solvent gives the product (2.82 g, 85%) as a pale yellow residue which is pure by NMR. 1H-NMR (CDCl3, 300 MHz) δ 0.93 (d, 6H, J=6.5 Hz, CH(CH3)2); 1.96 (m, 1H, CH(CH3)2); 2.22 (s, 6H, N(CH3)2); 2.52, 2.78 (2 m, 2H each, CH2CH2NHMe2); 3.97 (d, 2H, J=6.5 Hz, OCH2); 6.85 (s, 1H, H-2); 7.04 (d, 1H, J=7.6 Hz, H-7); 7.41 (dd, 1H, J=1.5 Hz, H-6); 7.61 (bs, 1H, H-4); 7.86 (br s, 1H, N═CH); 9.43 (br s, 1H, NH); 9.82 (br s, 1H, H-1). 13C-NMR (CDCl3, 75 MHz) δ 19.36 (CH(CH3)2); 23.59 (CH2); 28.39 (CH(CH3)2); 45.53 (N(CH3)2); 60.32 (CH2NMe2); 71.87 (OCH2); 112.20 (C-7); 114.21 (C-3); 119.35 (C-4); 120.58 (C-6); 123.41 (C-2); 125.17 (C-5); 127.48 (C-9); 137.76 (C-8); 146.80 (N═CH); 154.91 (NC═O).

Provenance & Evidence