Hydrochloric Acid → 4-nitro-phenyl-4H-thieno[3,2-b]pyrrole-5-carboxylic acid ethyl ester

HRID 1713040Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[NH:10][C:9]2[CH:11]=[CH:12][S:13][C:8]=2[CH:7]=1)=[O:5])[CH3:2].[N+:14]([C:17]1[CH:22]=[CH:21][C:20](O)=[C:19](I)[CH:18]=1)([O-:16])=[O:15].C([O-])(=O)C.[Na+].Cl>CC(N(C)C)=O.C(OCC)(=O)C>[CH2:1]([O:3][C:4]([C:6]1[NH:10][C:9]2[CH:11]=[C:12]([C:20]3[CH:21]=[CH:22][C:17]([N+:14]([O-:16])=[O:15])=[CH:18][CH:19]=3)[S:13][C:8]=2[CH:7]=1)=[O:5])[CH3:2]

Participants

Conditions

Temperature: 150 °C

Procedure

The resulting fused thiophene-pyrrole product, 4H-thieno[3,2-b]pyrrole-5-carboxylic acid ethyl ester (250 mg, 1.28 mmol) and 4-nitro-iodophenol (266 mg, 1.07 mmol) were dissolved in dimethylacetamide (10 ml). Sodium acetate (209.6 mg, 1.6 mmol) and tetrakis-(triphenylphosphine)palladium (61.8 mg, 0.005 mmol) were added thereafter and the reaction mixture was heated at 150° C. while stirring for 24 hours. A solution of HCl 0.1 M (50 ml) and ethyl acetate (20 ml) was then added, the organic and aqueous phases were separated, and the aqueous phase was extracted with ethyl acetate (3×20 ml). The combined organic phase was dried over Na2SO4 and the organic solvents were evaporated under reduced pressure. The crude product was purified by silica gel flash chromatography to give 105.5 mg of pure 2-(4-nitro-phenyl-4H-thieno[3,2-b]pyrrole-5-carboxylic acid ethyl ester (yield 31.2%).

Workup

customthe organic and aqueous phases were separated
extractionthe aqueous phase was extracted with ethyl acetate (3×20 ml)
dry with materialThe combined organic phase was dried over Na2SO4
customthe organic solvents were evaporated under reduced pressure
customThe crude product was purified by silica gel flash chromatography

Sources & evidence

ORD record: ord-4f7de3b89ec540c3805e7a821f9cb7e3
Source dataset: uspto-grants-2010_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07795255B2

Reaction notes

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