Methyl iodide → HCID 71279836, compound

Temperature

0 °C

To a solution of 3-iodo-1H-thieno[3,2-c]pyrazole (500 mg, 2.0 mmol) in THF (7 ml) at 0° C. was added KOt-Bu (314 mg, 2.8 mmol). The reaction mixture was stirred at 0° C. for 30 min then added iodomethane (0.17 ml, 2.8 mmol). Stirred at 0° C. for 30 min then warmed to room temperature and stirred for 1.5 h. The reaction was quenched with water and extracted with EtOAc (2×). The combined organics were washed with brine then dried over MgSO4 and concentrated. The crude residue was purified by silica gel chromatography with 20% to 50% EtOAc/heptane to afford 292 mg (55%) of 3-iodo-1-methyl-1H-thieno[3,2-c]pyrazole as a light brown viscous oil. 1H NMR (CDCl3, 300 MHz): δ (ppm) 7.41 (d, J=5.3 Hz, 1H), 6.97 (d, J=5.3 Hz, 1H), 4.05 (s, 3H). Also isolated 141 mg (27%) of 3-iodo-2-methyl-2H-thieno[3,2-c]pyrazole as an off-white solid. 1H NMR (CDCl3, 300 MHz): δ (ppm) 7.36 (d, J=5.3 Hz, 1H), 7.16 (d, J=5.3 Hz, 1H), 4.13 (s, 3H).

1. stirringStirred at 0° C. for 30 min
2. temperaturethen warmed to room temperature
3. stirringstirred for 1.5 h
4. customThe reaction was quenched with water
5. extractionextracted with EtOAc (2×)
6. washThe combined organics were washed with brine
7. dry with materialthen dried over MgSO4
8. concentrationconcentrated
9. customThe crude residue was purified by silica gel chromatography with 20% to 50% EtOAc/heptane

ORD record

ord-5ef64902ce0b4bcbbd411dc3d5c027fe

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658646B2