hydroxylamine-O-sulfonic acid → 5-Methylthiophene-3-sulfonamide

To a solution of the above prepared 5-methyl-thiophene-3-sulfonic acid lithium salt (1.100 g, 6.03 mmol) in 5.0 ml of water was added 0.792 g of sodium acetate (1.6 eq.) and 1.024 g of hydroxylamine-O-sulfonic acid (1.5 eq.), and this mixture was stirred for 2 h at room temperature. HPLC showed complete conversion to the product. The reaction mixture was then partitioned between ethyl acetate and water, the layers were separated, the organic phase was washed with citric acid (10% in water), water and brine, dried over sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica column chromatography (SiO2, hexane/ethyl acetate), to yield finally 0.745 g of the title compound as light yellow solid of mp. 105-106.5° C.

1. customThe reaction mixture was then partitioned between ethyl acetate and water
2. customthe layers were separated
3. washthe organic phase was washed with citric acid (10% in water), water and brine
4. dry with materialdried over sodium sulfate
5. customthe solvent was evaporated under reduced pressure
6. customThe residue was purified by silica column chromatography (SiO2, hexane/ethyl acetate)

ORD record

ord-fc91efd39c724c09b8cae3106c50fd84

Source dataset

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07973051B2