Water → HCID 178519296, compound

Participants

Reaction Steps

A 150 ml round-bottomed flask equipped with a magnetic stirrer and with a septum having a top-mounted argon intake is charged with 1 g of 3-bromo-5-(2,6-difluorophenyl)-7-vinyl-1H-pyrazolo[4,3-c]isoquinoline in 13 ml of THF and then 7 ml of water, 13 ml of tert-butanol, 0.79 ml of a solution of osmium tetroxide at 2.5% in 2-methyl-2-propanol, and 17 g of sodium periodate are added. The mixture is stirred at RT for 3 h and then poured into water, extracted with AcOEt, washed with saturated NaCl solution, dried over MgSO4, filtered and concentrated under RP. This gives 1.047 g of a crude product, which is purified by chromatography on silica gel (20-45 μm), eluting with a mixture of DCM and methanol (95/5 by vol.), to give 686 mg of 3-bromo-5-(2,6-difluorophenyl)-1H-pyrazolo[4,3-c]isoquinoline-7-carbaldehyde (cream solid). MS (E/I): m/z=388 (M+); 1H NMR: 7.41 (d, J=7.9 Hz, 2H); 7.77 (m, 1H); 8.34 (broad s, 1H); 8.47 (dd, J=8.5, 1.2 Hz, 1H); 8.69 (d, J=8.5 Hz, 1H); 10.15 (s, 1H); 14.89 (broad m, 1H).

Provenance & Evidence