Ethanol → ethyl 3-(5-amino-3-tert-butyl-1H-pyrazol-1-yl)benzoate
Reaction equation
Cl.[NH:2]([C:4]1[CH:5]=[C:6]([CH:10]=[CH:11][CH:12]=1)[C:7]([OH:9])=[O:8])[NH2:3].[CH3:13][C:14]([CH3:21])([CH3:20])[C:15](=O)[CH2:16][C:17]#[N:18].[CH3:22][CH2:23]O>>[CH2:22]([O:8][C:7](=[O:9])[C:6]1[CH:10]=[CH:11][CH:12]=[C:4]([N:2]2[C:17]([NH2:18])=[CH:16][C:15]([C:14]([CH3:21])([CH3:20])[CH3:13])=[N:3]2)[CH:5]=1)[CH3:23].[NH2:18][C:17]1[N:2]([C:4]2[CH:5]=[C:6]([CH:10]=[CH:11][CH:12]=2)[C:7]([OH:9])=[O:8])[N:3]=[C:15]([C:14]([CH3:21])([CH3:20])[CH3:13])[CH:16]=1Participants
5
Procedure
A mixture of 3-hydrazinobenzoic acid hydrochloride (200 g, 1.06 mol) and 4,4-dimethyl-3-oxopentanenitrile (146 g, 1.167 mol) in EtOH (2 L) was heated at reflux overnight. The reaction solution was evaporated under reduced pressure. The residue was purified by column chromatography to give 3-(5-amino-3-t-butyl-pyrazol-1-yl)-benzoic acid ethyl ester (116 g, 40%) as a white solid together with 3-(5-amino-3-t-butyl-pyrazol-1-yl)benzoic acid (93 g, 36%). 3-(5-amino-3-t-butyl-pyrazol-1-yl)benzoic acid and ethyl ester. 1H NMR (400 MHz, DMSO-d6): δ 8.09 (s, 1H), 8.05 (brd, J=8.0 Hz, 1H), 7.87 (brd, J=8.0 Hz, 1H), 7.71 (t, J=8.0 Hz, 1H), 5.64 (s, 1H), 4.35 (q, J=7.2 Hz, 2H), 1.34 (t, J=7.2 Hz, 3H), 1.28 (s, 9H).
Workup
- temperaturewas heated
- temperatureat reflux overnight
- customThe reaction solution was evaporated under reduced pressure
- customThe residue was purified by column chromatography
Sources & evidence
- ORD record
- ord-5484d9bfdfa94e3eb42754178907dc18
- Source dataset
- uspto-grants-2012_04
- Patent number
- US08163756B2
Reaction notes
Loading…