Cyanoacetamide → 2-Aminothiophene-3-carboxamide

To a solution of 2,5-dihydroxy-1,4-dithiane (10 g, 65.78 mmol) in ethanol (200 mL) and triethylamine (2 mL) was added cyanoacetamide (5.52 g, 65.78 mmol) at rt for 5 min. The reaction mixture was refluxed for 3 h and attained to rt. Ethanol (appr. 150 mL) was removed under reduced pressure and poured the contents into ice cold water and stirred for 15 min. The solution was extracted with ethyl acetate (3×100 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:5) as eluents to give the product as a pale yellow color solid (4.9 g, 53%), mp 150-152° C.

1. temperatureThe reaction mixture was refluxed for 3 h
2. customattained to rt
3. customEthanol (appr. 150 mL) was removed under reduced pressure
4. additionpoured the contents into ice cold water
5. extractionThe solution was extracted with ethyl acetate (3×100 mL)
6. washthe combined EtOAc layer was washed with water, brine
7. dry with materialdried over sodium sulfate
8. filtrationThe solution was filtered
9. customevaporated the solvent
10. customThe residue was chromatographed over silica gel column

ORD record

ord-54e8939fe63c415eac5693d4c1495e04

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08258119B2