Methanol → Methyl 2-tert-butyl-5-nitro-1H-indole-7-carboxylate
Reaction equation
O=S(Cl)Cl.[C:5]([C:9]1[NH:10][C:11]2[C:16]([CH:17]=1)=[CH:15][C:14]([N+:18]([O-:20])=[O:19])=[CH:13][C:12]=2[C:21]([OH:23])=[O:22])([CH3:8])([CH3:7])[CH3:6].[CH3:24]O>>[C:5]([C:9]1[NH:10][C:11]2[C:16]([CH:17]=1)=[CH:15][C:14]([N+:18]([O-:20])=[O:19])=[CH:13][C:12]=2[C:21]([O:23][CH3:24])=[O:22])([CH3:8])([CH3:6])[CH3:7]Participants
4
Conditions
- Temperature
- 80 °C
Procedure
SOCl2 (3.6 g, 30 mol) was added dropwise to a solution of 2-tert-butyl-5-nitro-1H-indole-7-carboxylic acid (4.0 g, 15 mol) and methanol (30 mL) at 0° C. The mixture was stirred at 80° C. for 12 h. The solvent was evaporated under vacuum and the residue was purified by column chromatography on silica gel (5% EtOAc in petroleum ether) to afford methyl 2-tert-butyl-5-nitro-1H-indole-7-carboxylate (2.95 g, 70%). 1H NMR (CDCl3, 300 MHz) δ 9.99 (brs, 1H), 8.70 (d, J=2.1 Hz, 1H), 8.65 (d, J=2.1 Hz, 1H), 6.50 (d, J=2.4 Hz, 1H), 4.04 (s, 3H), 1.44 (s, 9H).
Workup
- customThe solvent was evaporated under vacuum
- customthe residue was purified by column chromatography on silica gel (5% EtOAc in petroleum ether)
Sources & evidence
- ORD record
- ord-5e47cffd1dc74c4c9baa155be49c9f0c
- Source dataset
- uspto-grants-2013_12
- Patent number
- US08598181B2
Reaction notes
Loading…