2-Bromo-4'-nitroacetophenone → Ethyl 2-amino-5-(4-nitrophenyl)-1H-pyrrole-3-carboxylate

HRID 369859Notes

Reaction equation

HRID 369859 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:24]=[CH:23][C:22]([N+:25]([O-:27])=[O:26])=[CH:21][CH:20]=1)=O>C(O)C>[NH2:9][C:7]1[NH:8][C:17]([C:19]2[CH:20]=[CH:21][C:22]([N+:25]([O-:27])=[O:26])=[CH:23][CH:24]=2)=[CH:16][C:6]=1[C:5]([O:4][CH2:2][CH3:3])=[O:10]

Participants

5

Reactant 3

HCID 668402-Bromo-4'-nitroacetophenoneHCID 2723922Sodium ethoxideHCID 15555354Ethyl 2-carbamimidoylacetate hydrochloride

Product 1

HCID 21262647Ethyl 2-amino-5-(4-nitrophenyl)-1H-pyrrole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

In a dry three-necked flask, under argon, 75 ml of abs. ethanol and 6.5 g (390 mmol) of 2-amidino-acetic acid ethyl ester hydrochloride [for preparation see: Liebigs Ann. Chem., 1895 (1977)] are cooled to 0-5° C. and 2.65 g (390 mmol) of sodium ethanolate are added thereto. Then 5 g (195 mmol) of 2-bromo-1-(4-nitro-phenyl)-ethan-1-one are added and the reaction mixture is allowed to come to RT and then stirred for 48 hours. The reaction mixture is then partitioned between water and ethyl acetate. The ethyl acetate phase is washed three times with water and once with saturated NaCl solution, dried and filtered and the filtrate is concentrated by evaporation. The red-brown residue is suspended in hexane and the title compound precipitates in the form of the crude product (purity 93%), which is used for the next step without further purification; MS: (M)+ =275.

Workup

  1. customto come to RT
  2. customThe reaction mixture is then partitioned between water and ethyl acetate
  3. washThe ethyl acetate phase is washed three times with water
  4. dry with materialonce with saturated NaCl solution, dried
  5. filtrationfiltered
  6. concentrationthe filtrate is concentrated by evaporation
  7. customthe title compound precipitates in the form of the crude product (purity 93%), which
  8. customis used for the next step without further purification

Sources & evidence

ORD record
ord-8e3fc2639a3c452f867b1e08431fd2ca
Source dataset
uspto-grants-2000_10
Patent number
US06140332

Reaction notes

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