Dimethylformamide → Methyl 5-amino-2-phenylcyclopenta-1,3-dienecarboxylate
Reaction equation
[C:1]1([C:7]2[CH:11]=[CH:10]N[C:8]=2[C:12]([O:14][CH3:15])=[O:13])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[H-].[Na+].NCl.[CH3:20][N:21](C=O)C>>[NH2:21][CH:20]1[C:8]([C:12]([O:14][CH3:15])=[O:13])=[C:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[CH:11]=[CH:10]1Participants
Procedure
To a solution of methyl 3-phenyl-1H-pyrrole-2-carboxylate (2.50 g, 12.4 mmol) in DMF (25 mL) was added NaH (0.358 g, 14.9 mmol) and the reaction mixture was stirred for 45 min at room temperature. Monochloramine (0.15 M, 150 mL, 0.225 g, 4.40 mmol) was added via syringe. The reaction was stirred for 2 h and was quenched by the addition of saturated aqueous sodium thiosulfite. The reaction mixture was diluted with water and the aqueous portion extracted with ethyl acetate. The organic layer dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography using CombiFlash (REDISEP®, neutral alumina, 40 g, 25% EtOAc/hexanes) to afford methyl 5-amino-2-phenylcyclopenta-1,3-dienecarboxylate (2.20 g, 82.0%). LCMS Condition B-38: retention time 1.79 min, [M+1]=217.0. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.63 (s, 3H), 6.07 (d, J=2.8 Hz, 1H), 6.28 (s, 2H), 7.05 (d, J=2.8 Hz, 1H), 7.33-7.35 (m, 5H).
Workup
- stirringThe reaction was stirred for 2 h
- customwas quenched by the addition of saturated aqueous sodium thiosulfite
- additionThe reaction mixture was diluted with water
- extractionthe aqueous portion extracted with ethyl acetate
- dry with materialThe organic layer dried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated under reduced pressure
- customThe residue was purified by column chromatography
Sources & evidence
- ORD record
- ord-efd7604eddb34bb9a86e18e49477c34e
- Source dataset
- uspto-grants-2015_06
- Patent number
- US09050345B2
Reaction notes
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