Hydrochloric Acid → 5,6-Dihydro-2H-thiopyran-3-carboxamide

To a solution of 5,6-dihydro-2H-thiopyran-3-carboxylic acid (0.84 g, 5.8 mmol) in DMF (29 mL) was added DIPEA (3.4 g, 26 mmol), followed by TBTU (4.1 g, 13 mmol). The resulting mixture was stirred at ambient temperature for 30 minutes, then HMDS (2.1 g, 13 mmol) was added. The mixture was stirred at ambient temperature for 16 hours. The reaction mixture was acidified with 1N aqueous HCl, and extracted with EtOAc (3×). The combined organic extracts were again washed with 1N aqueous HCl, brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The crude residue was purified by MPLC on silica gel (using a gradient elution of 0-5% MeOH/DCM). Desired fractions were identified, combined and concentrated in vacuo to afford the title compound. 1H NMR (500 MHz, CDCl3): δ 6.68-6.69 (m, 1H); 3.38 (q, J=2.2 Hz, 2H); 2.70 (t, J=5.8 Hz, 2H); 2.50-2.51 (m, 2H).

1. stirringThe mixture was stirred at ambient temperature for 16 hours
2. extractionextracted with EtOAc (3×)
3. washThe combined organic extracts were again washed with 1N aqueous HCl, brine
4. dry with materialdried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude residue was purified by MPLC on silica gel (
8. washa gradient elution of 0-5% MeOH/DCM)
9. concentrationconcentrated in vacuo

ORD record

ord-feb0ee0103da4daa8a05d94417592741

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394282B2