Butanedione → 3-(2,5-Diphenyl-pyrrol-1-ylimino)-butan-2-one

HRID 1265287Notes

Reaction equation

HRID 1265287 reaction equation
[C:1]1([C:7]2[N:8]([NH2:18])[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)=[CH:10][CH:11]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH3:19][C:20](=O)[C:21](=[O:23])[CH3:22].CN(C=O)C.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[C:12]1([C:9]2[N:8]([N:18]=[C:20]([CH3:19])[C:21](=[O:23])[CH3:22])[C:7]([C:1]3[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=3)=[CH:11][CH:10]=2)[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1

Participants

6

Reactant 4

HCID 650ButanedioneHCID 6101p-Toluenesulfonic acidHCID 6228DimethylformamideHCID 44562452,5-Diphenyl-pyrrol-1-ylamine

Product 1

HCID 571252783-(2,5-Diphenyl-pyrrol-1-ylimino)-butan-2-one

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A suspension of 2,5-Diphenyl-pyrrol-1-ylamine (1.91 g, 8.15 mmol) in toluene (5.45 mL) was treated with 2,3-butanedione (7.15 mL, 81.5 mmol), DMF (10.9 mL) and p-toluene sulfonic acid (10.9 mg). The resulting suspension was stirred under Ar at rt for 30 min, then heated to 70° C. in an oil bath. After 2.5 h, the solutions cooled to rt and concentrated in vacuo. The oily solid was dissolved in toluene and concentrated in vacuo to remove excess 2,3-butanedione. The residue was purified by flash chromatography (SiO2, 10% EtOAc/heptane) to afford 3-(2,5-Diphenyl-pyrrol-1-ylimino)-butan-2-one: 1H NMR (CDCl3, chemical shifts in ppm relative to TMS): 1.44 (s, 3H), 2.56 (s, 3H), 6.47 (s, 2H), 7.20-7.26 (m, 2H), 7.34 (t, 4H, J=8.0 Hz), 7.47 (d, 4H, J=8.0 Hz).

Workup

  1. temperatureheated to 70° C. in an oil bath
  2. waitAfter 2.5 h
  3. temperaturethe solutions cooled to rt
  4. concentrationconcentrated in vacuo
  5. dissolutionThe oily solid was dissolved in toluene
  6. concentrationconcentrated in vacuo
  7. customto remove excess 2,3-butanedione
  8. customThe residue was purified by flash chromatography (SiO2, 10% EtOAc/heptane)

Sources & evidence

ORD record
ord-37283298f7b944a68d1b6dbce4c657b2
Source dataset
uspto-grants-2003_04
Patent number
US06545108B1

Reaction notes

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