Methyl 5-nitrothiophene-3-carboxylate → Methyl 5-aminothiophene-3-carboxylate

To a solution of 5-nitro-thiophene-3-carboxylic acid methyl ester (0.5 g, 2.67 mmol) in aqueous acetic acid (5 ml) was added iron powder (1.04 g, 18.6 mmol) and the reaction mixture was heated to reflux for 3 hr. The reaction mixture was filtered and triethylamine was added to the filtrate. The compound was extracted with ethyl acetate and the organic layer was washed with water, concentrated and dried to yield crude compound. The compound was purified by silica gel column chromatography, using ethyl acetate/hexane as eluent, to yield 5-amino-thiophene-3-carboxylic acid methyl ester (0.1 g, 24%).

1. temperaturethe reaction mixture was heated
2. temperatureto reflux for 3 hr
3. filtrationThe reaction mixture was filtered
4. additiontriethylamine was added to the filtrate
5. extractionThe compound was extracted with ethyl acetate
6. washthe organic layer was washed with water
7. concentrationconcentrated
8. customdried
9. customto yield crude compound
10. customThe compound was purified by silica gel column chromatography

ORD record

ord-8665354c5f57499a8919b68a4dabffcf

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08486962B2