Hydrochloric Acid → Methyl 3-amino-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate

HRID 2380787Notes

Reaction equation

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

Participants

Conditions

Temperature: 70 °C

Procedure

To a solution of methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (0.9 g, 3.27 mmol) in methanol (20 mL) was added conc. Hydrochloric acid (0.3 mL). To the above solution was added iron powder (0.91 g, 16.36 mmol) followed by an aqueous solution of ammonium chloride (0.87 g, 16.3 mmol, water: 5 mL) at rt. The reaction mixture was stirred and warmed to 70° C. for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with ethyl acetate (4×100 mL). The combined organic layer was washed with brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as a pale yellow color solid (0.65 g, 81%), mp 120-124° C. NMR (400 MHz, CDCl3): δ 5.39 (2H, br s), 4.01 (3H, s), 3.87 (3H, s), 3.85 (3H, s); LC-MS (positive ion mode): m/z 246 (M+H)+.

Workup

temperatureto cool to rt
filtrationThe solution was filtered
extractionThe solution was extracted with ethyl acetate (4×100 mL)
washThe combined organic layer was washed with brine
dry with materialdried over sodium sulfate
filtrationThe solution was filtered
customevaporated the solvent

Sources & evidence

ORD record: ord-336cd48ce35c4bbabf66dbf08556e7ac
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08258119B2

Reaction notes

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