2-Bromo-2'-acetonaphthone → 2-Amino-3-ethoxycarbonyl-5-(naphth-2-yl)-1H-pyrrole

HRID 369842

Reaction equation

HRID 369842 reaction equation
Cl.[CH2:2]([O:4][C:5](=[O:10])[CH2:6][C:7](=[NH:9])[NH2:8])[CH3:3].C([O-])C.[Na+].Br[CH2:16][C:17]([C:19]1[CH:28]=[CH:27][C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[CH:20]=1)=O>C(O)C>[NH2:9][C:7]1[NH:8][C:17]([C:19]2[CH:28]=[CH:27][C:26]3[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=3)[CH:20]=2)=[CH:16][C:6]=1[C:5]([O:4][CH2:2][CH3:3])=[O:10]

Participants

5

Reactant 3

HCID 691792-Bromo-2'-acetonaphthoneHCID 2723922Sodium ethoxideHCID 15555354Ethyl 2-carbamimidoylacetate hydrochloride

Product 1

HCID 232827142-Amino-3-ethoxycarbonyl-5-(naphth-2-yl)-1H-pyrrole

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Under an argon atmosphere, 834 mg (5 mmol) of 2-amidino-acetic acid ethyl ester hydrochloride [for preparation see: Liebigs Ann. Chem., 1895 (1977)] are introduced into 10 ml of ethanol and, at 0-5° C., 358 mg (5 mmol) of sodium ethanolate are added thereto. The bright yellow suspension is stirred for 15 min and then 623 mg (2.5 mmol) of 2-bromo-1-(naphth-2-yl)-ethan-1-one (2-bromo-2'-acetonaphthone; Aldrich; Milwaukee/USA) are added thereto. After 3 days' stirring at RT, the reaction mixture is concentrated by evaporation. The residue is taken up in ethyl acetate/water and filtered and the organic phase is separated off and washed with 3 portions of water and brine. The aqueous phases are extracted with ethyl acetate and the organic phases are dried over MgSO4 and concentrated by evaporation. Column chromatography (SiO2 ; ethyl acetate/hexane [1:1]) and stirring in diethyl ether/hexane yield the title compound; m.p. 149-151° C.; TLC-Rf =0.5 (ethyl acetate/hexane [1:1]); FAB-MS: (M+H)+ =281.

Workup

  1. stirringAfter 3 days' stirring at RT
  2. concentrationthe reaction mixture is concentrated by evaporation
  3. filtrationfiltered
  4. customthe organic phase is separated off
  5. washwashed with 3 portions of water and brine
  6. extractionThe aqueous phases are extracted with ethyl acetate
  7. dry with materialthe organic phases are dried over MgSO4
  8. concentrationconcentrated by evaporation
  9. stirringColumn chromatography (SiO2 ; ethyl acetate/hexane [1:1]) and stirring in diethyl ether/hexane

Sources & evidence

ORD record
ord-684db247d16444ceb5214f7359703915
Source dataset
uspto-grants-2000_10
Patent number
US06140332

Linked notes

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