Methanol → methyl 2-tert-butyl-5-nitro-4H-indole-7-carboxylate

HRID 468352Notes

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[CH:17]=[C:16]2[C:11](=[C:12]([C:21]([O:23][CH3:24])=[O:22])[CH:13]=[C:14]([N+:18]([O-:20])=[O:19])[CH2:15]2)[N:10]=1)([CH3:8])([CH3:6])[CH3:7]

Participants

Reactant 3

HCID 887Methanol

HCID 24386Thionyl Chloride

HCID 534211852-Tert-butyl-5-nitro-1H-indole-7-carboxylic acid

Product 1

HCID 67269975methyl 2-tert-butyl-5-nitro-4H-indole-7-carboxylateYield 70%

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-4H-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-ffd3950473814344b2f4f589604f6ed6
Source dataset: uspto-grants-2014_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08623905B2

Reaction notes

Loading…