Ethanol → 5-Amino-4-(3-bromo-benzenesulfonyl)-thiophene-2-carboxylic acid methyl ester

HRID 723047Notes

Reaction equation

[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([N+:20]([O-])=O)=[C:8]([S:10]([C:13]2[CH:18]=[CH:17][CH:16]=[C:15]([Br:19])[CH:14]=2)(=[O:12])=[O:11])[CH:9]=1)=[O:4].CCO.[Cl-].[NH4+]>[Fe].O>[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([NH2:20])=[C:8]([S:10]([C:13]2[CH:18]=[CH:17][CH:16]=[C:15]([Br:19])[CH:14]=2)(=[O:11])=[O:12])[CH:9]=1)=[O:4]

Participants

Conditions

Temperature: 50 °C

Procedure

4-(3-Bromo-benzenesulfonyl)-5-nitro-thiophene-2-carboxylic acid methyl ester (407 mg, 1.0 mmol, Example 20: step b) was dissolved into EtOH (6 mL). To this was added ammonium chloride (535 mg, 10 mmol) dissolved into water (3 mL). This mixture was heated to 50° C. with stirring and then iron (277 mg, 5 mmol) was added. The reaction was then heated to 80° C. with stirring for 12 hours. The reaction mixture was then filtered through Celite® and washed with 10% DCM/MeOH. Removal of the solvents in vacuo yielded the title compound (598 mg, quantitative yield) which was used without further purification. 1H-NMR (CDCl3): δ 8.05 (s, 1H), 7.84–7.86 (m, 1H), 7.70–7.75 (m, 1H), 7.56 (s, 1H), 7.40 (m, 1H), 6.02 (br s, 2H), 3.85 (s, 3H). ESI-MS (m/z): Calcd. for C12H10BrNO4S2: 375.9 (M+H); found: 376.1.

Workup

temperatureThe reaction was then heated to 80° C.
stirringwith stirring for 12 hours
filtrationThe reaction mixture was then filtered through Celite®
washwashed with 10% DCM/MeOH
customRemoval of the solvents in vacuo

Sources & evidence

ORD record: ord-939a156c4a8545d5b2cca3bd64e3e475
Source dataset: uspto-grants-2006_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07138530B2

Reaction notes

Loading…