Pyrrole → HCID 136044060, compound

HRID 1037802Notes

Reaction equation

HRID 1037802 reaction equation
[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([CH3:8])[N:4]=[C:3]1[CH:9]=O.[NH:11]1[CH:15]=[CH:14][CH:13]=[CH:12]1>C(O)(=O)CC>[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([CH3:8])[N:4]=[C:3]1[C:9]1[C:15]2[NH:11][C:12]([C:9]([C:3]3[N:2]([CH3:1])[C:6]([CH3:7])=[C:5]([CH3:8])[N:4]=3)=[C:12]3[N:11]=[C:15]([C:9]([C:3]4[N:2]([CH3:1])[C:6]([CH3:7])=[C:5]([CH3:8])[N:4]=4)=[C:12]4[NH:11][C:15](=[C:9]([C:3]5[N:2]([CH3:1])[C:6]([CH3:7])=[C:5]([CH3:8])[N:4]=5)[C:12]5[CH:13]=[CH:14][C:15]=1[N:11]=5)[CH:14]=[CH:13]4)[CH:14]=[CH:13]3)=[CH:13][CH:14]=2

Participants

4

Reactant 2

HCID 8027PyrroleHCID 186124001,4,5-Trimethyl-1H-imidazole-2-carbaldehyde

Product 1

HCID 136044060HCID 136044060, compound

Reagents, catalysts & solvents 1

HCID 1032Propionic AcidSolvent

Procedure

1,4,5-Trimethylimidazole-2-carboxaldehyde (37, 750 mg, 5.42 mmol), prepared according to literature procedure (Alcalde, E. et al., Tetrahedron 52:15171-15188 (1996)), was dissolved in propionic acid (120 mL) in a 250 mL three neck round-bottom flask equipped with a thermometer and a condenser. The solution was heated to reflux then pyrrole (0.38 mL, 5.42 mmol) was added. The reaction mixture was heated at reflux for an additional 5 h, then cooled to room temperature while exposed to air overnight. The propionic acid was removed by vacuum distillation yielding a dark solid residue which was adsorbed onto silica gel. Purification by column chromatography (gradient elution 5-10% MeOH/CH2Cl2) provided porphyrin 38 as a mixture of atropisomers (108 mg, 10.7%). 1H NMR (300 MHz, CDCl3)*−2.90, −2.85, −2.78 (3 s, 2H, atropisomer NH), 2.50 (s, 12 H), 2.57 (s, 12 H), 3.15-3.42 (multiple s, 12 H, atropisomer N—CH3), 8.91 (multiple s, 8 H, atropisomer).

Workup

  1. customequipped with a thermometer and a condenser
  2. temperatureThe solution was heated
  3. temperatureto reflux
  4. temperatureThe reaction mixture was heated
  5. temperatureat reflux for an additional 5 h
  6. customThe propionic acid was removed by vacuum distillation
  7. customyielding a dark solid residue which
  8. customPurification
  9. washby column chromatography (gradient elution 5-10% MeOH/CH2Cl2)

Sources & evidence

ORD record
ord-26bae2ebf3a8484f9b064834e0613a44
Source dataset
uspto-grants-2013_10
Patent number
US08546562B2

Reaction notes

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