Reaction equation
[N+:1]([C:4]1[CH:10]=[C:9]([C:11]([CH3:14])([CH3:13])[CH3:12])[CH:8]=[CH:7][C:5]=1[NH2:6])([O-:3])=[O:2].CC(O)=O.[CH2:19]([CH2:23][C:24](=O)[CH3:25])[C:20]([CH3:22])=O>C1CCCCC1.C(Cl)Cl>[C:11]([C:9]1[CH:8]=[CH:7][C:5]([N:6]2[C:24]([CH3:25])=[CH:23][CH:19]=[C:20]2[CH3:22])=[C:4]([N+:1]([O-:3])=[O:2])[CH:10]=1)([CH3:14])([CH3:13])[CH3:12]Participants
Conditions
- Temperature
- 120 °C
Procedure
To a stirring solution of 2-nitro-4-tert-butylaniline (0.5 g, 2.57 mmol) in cyclohexane (10 mL) was added AcOH (0.1 mL) and acetonylacetone (0.299 g, 2.63 mmol) via syringe. The reaction mixture was heated at 120° C. for 72 h with azeotropic removal of volatiles. The reaction mixture was cooled to room temp., diluted with CH2Cl2 (10 mL) and sequentially washed with a 1N HCl solution (15 mL), a 1N NaOH solution (15 mL) and a saturated NaCl solution (15 mL), dried (MgSO4) and concentrated under reduced pressure. The resulting orange-brown solids were purified via column chromatography (60 g SiO2; gradient from 6% EtOAc/94% hexane to 25% EtOAc/75% hexane) to give 1-(4-tert-butyl-2-nitrophenyl)-2,5-dimethylpyrrole as an orange-yellow solid (0.34 g, 49%): TLC (15% EtOAc/85% hexane) Rf 0.67; 1H NMR (CDCl3) d 1.34 (s, 9H), 1.89 (s, 6H), 5.84 (s, 2H), 7.19-7.24 (m, 1H), 7.62 (dd, 1H), 7.88 (d, J=2.4 Hz, 1H); CI-MS m/z 273 ((M+H)+, 50%).
Workup
- temperatureThe reaction mixture was cooled to room temp.
- washsequentially washed with a 1N HCl solution (15 mL)
- dry with materiala 1N NaOH solution (15 mL) and a saturated NaCl solution (15 mL), dried (MgSO4)
- concentrationconcentrated under reduced pressure
- customThe resulting orange-brown solids were purified via column chromatography (60 g SiO2; gradient from 6% EtOAc/94% hexane to 25% EtOAc/75% hexane)
Sources & evidence
- ORD record
- ord-a5e49218770b4e6592a290fe6c15694c
- Source dataset
- uspto-grants-2009_05
- Patent number
- US07528255B2
Linked notes
Loading…