tert-Butanol → tert-Butyl thiophen-2-ylcarbamate

Temperature

90 °C

To a solution of thiophenecarboxylic acid (0.5 g, 3.90 mmol) in tBuOH (10 ml) was added Et3N (0.571 ml, 4.10 mmol) and DPPA (0.883 ml, 4.10 mmol). The solution was heated at 90° C. for 4 hours. The reaction mixture was cooled to RT and the solvent was removed in vacuo. The residue was treated with benzene and then the solution was washed with 5% citric acid, and sat'd NaHCO3. Solid was filtered off and the filtrate was washed with brine. The organic layer was dried (MgSO4), concentrated in vacuo and the residue was purified by silica gel column chromatography (EtOAc/hexanes) to obtain tert-butyl thiophen-2-ylcarbamate (0.39 g, 50% yield). 1H NMR (400 MHz, DMSO-d6): δ 10.4 (brs, 1H), 6.84 (dd, J=1.6, and 5.2 Hz, 1H), 6.75 (dd, J=4.0, and 5.6 Hz, 1H), 6.48 (dd, J=1.6, and 4.0 Hz, 2H), 1.45 (s, 9H); MS (ESI) m/z: 222.0 (M+22+H+).

1. temperatureThe reaction mixture was cooled to RT
2. customthe solvent was removed in vacuo
3. additionThe residue was treated with benzene
4. washthe solution was washed with 5% citric acid
5. filtrationSolid was filtered off
6. washthe filtrate was washed with brine
7. dry with materialThe organic layer was dried (MgSO4)
8. concentrationconcentrated in vacuo
9. customthe residue was purified by silica gel column chromatography (EtOAc/hexanes)

ORD record

ord-5fca71198a7642f3b54201fa6c4357b7

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08486951B2