Acetic Acid → 1H-Pyrrole, 2,5-dimethyl-1-(phenylmethyl)-

HRID 1106386Notes

Reaction equation

HRID 1106386 reaction equation
[CH2:1]([NH2:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:9][C:10](=O)[CH2:11][CH2:12][C:13](=O)[CH3:14].C(O)(=O)C>C1(C)C=CC=CC=1.C(OC(C)C)(C)C>[CH3:14][C:13]1[N:8]([CH2:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)[C:10]([CH3:9])=[CH:11][CH:12]=1

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 7504BenzylamineHCID 80352,5-Hexanedione

Product 1

HCID 988071H-Pyrrole, 2,5-dimethyl-1-(phenylmethyl)-Yield 92.3%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 7914Diisopropyl EtherSolvent

Procedure

A mixture of benzylamine (10.7 g, 0.10 mol) and 2,5-hexanedione (11.4 g, 0.10 mol) and acetic acid (2.5 mL, 0.04 mol) in 50 mL toluene was heated at reflux under a Dean-Stark trap for 0.75hr. The resulting mixture was concentrated in vacuo to provide a viscous oil. The oil was dissolved in several volumes of isopropyl ether, then the solution was washed with 10% aqueous hydrochloric acid. The ether solution was dried and concentrated in vacuo to provide 2,5-dimethyl-1-benzylpyrrole (17.1 g, 92%) as a thick oil which eventually crystallized. The product was chromatographically homogenous and displayed an NMR spectrum consistent with its assigned structure. ##STR15## Preparation of Ethyl 2,5-Dimethyl-1-benzylindol-3-oyl-acetoacetate (I-3, a representative Friedel-Crafts acylation reaction):

Workup

  1. temperaturewas heated
  2. temperatureat reflux under a Dean-Stark trap for 0.75hr
  3. concentrationThe resulting mixture was concentrated in vacuo
  4. customto provide a viscous oil
  5. washthe solution was washed with 10% aqueous hydrochloric acid
  6. dry with materialThe ether solution was dried
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-89c09eaadbbf401f9ee9b252a1674ea9
Source dataset
uspto-grants-2000_05
Patent number
US06057087

Reaction notes

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