1-Bromo-2-Chloroethane → HCID 57625532, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromo-1H-indazole (900 mg, 4.57 mmol), 1-bromo-2-chloroethane (1.31 g, 9.14 mmol) and K2CO3 (1.89 g, 13 7 mmol) in DMF (40 mL) in a sealed pressure flask was heated at 40° C. for 10 h. Additional 1.3 g 1-bromo-2-chloroethane (1.31 g, 9.14 mmol), and K2CO3 (1.89 g, 13 7 mmol) were then added and heating was continued for 3 h. This was filtered, the solvent removed from the filtrate, and the residue chromatographed on silica gel (step gradient elution with hexane containing 0, 5, 10 and 20% EtOAc) afforded (in order of elution): 5-bromo-1-(2-chloroethyl)-1H-indazole (690 mg, 2.66 mmol, 58% yield). MS (ESI) m/z 260.95 (M+H). 1H NMR (500 MHz, chloroform-d) δ ppm 7.99 (1H, s), 7.88 (1H, s), 7.46-7.52 (1H, m), 7.36 (1H, d, J=8.85 Hz), 4.67 (2H, t, J=6.26 Hz), 3.97 (2H, t, J=6.26 Hz). 5-bromo-2-(2-chloroethyl)-2H-indazole (360 mg, 1.39 mmol, 30% yield). MS (ESI) m/z 260.95 (M+H). 1H NMR (500 MHz, chloroform-d) δ ppm 7.98 (1H, s), 7.85 (1H, s), 7.60 (1H, d, J=9.16 Hz), 7.37 (1H, d, J=9.16 Hz), 4.69-4.74 (2H, m), 4.02-4.07 (2H, m).

Provenance & Evidence