2,5-Hexanedione → Ethyl (2,5-dimethyl-1H-pyrrol-1-yl)acetate

HRID 1189550Notes

Reaction equation

HRID 1189550 reaction equation
Cl.[CH2:2]([O:4][C:5](=[O:8])[CH2:6][NH2:7])[CH3:3].[CH3:9][C:10](=O)[CH2:11][CH2:12][C:13](=O)[CH3:14].C(N(CC)CC)C.C([O-])(O)=O.[Na+]>ClCCl>[CH3:14][C:13]1[N:7]([CH2:6][C:5]([O:4][CH2:2][CH3:3])=[O:8])[C:10]([CH3:9])=[CH:11][CH:12]=1

Participants

6

Reactant 4

HCID 80352,5-HexanedioneHCID 8471TriethylamineHCID 516892Sodium BicarbonateHCID 2723640Glycine ethyl ester, hydrochloride

Product 1

HCID 12894114Ethyl (2,5-dimethyl-1H-pyrrol-1-yl)acetateYield 56%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

Glycine ethyl ester HCl (22 g, 158 mmol) was added to a stirring mixture of hexane-2,5-dione (18 g, 158 mmol) in dichloromethane (100 mL) in an Erlenmeyer flask. To the stirring heterogeneous mixture was slowly added triethylamine (66 mL, 473 mmol). After 30 minutes, dichloromethane (50 mL) and NaHCO3 (sat. aq. 100 mL) were added and the mixture continued to stir for 20 minutes. The dichloromethane layer was injected directly onto a 330 g silica gel column and the product was eluted with 0-100% ethyl acetate in hexanes. Pertinent fractions were combined and concentrated to afford ethyl 2-(2,5-dimethyl-1H-pyrrol-1-yl)acetate as a white solid (16 g, 56%). 1H NMR (CDCl3/400 MHz) δ (ppm) 5.8 (s, 2H), 4.85 (s, 2H), 4.22 (q, 2H), 2.17 (s, 6H), 1.28 (t, 3H)

Workup

  1. washthe product was eluted with 0-100% ethyl acetate in hexanes
  2. concentrationconcentrated

Sources & evidence

ORD record
ord-3c62f2ace5884a03a7172632e1f2bf3b
Source dataset
uspto-grants-2014_03
Patent number
US08674115B2

Reaction notes

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