Hydrochloric Acid → 5-(2,6-difluorophenyl)-3-{[1-(ethylsulphonyl)piperidin-4-yl]amino}-1H-pyrazolo[4,3-c]isoquinoline-7-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

A microwave tube with a maximum capacity of 20 ml is charged with 195 mg of 5-(2,6-difluorophenyl)-3-{[1-(ethylsulphonyl)piperidin-4-yl]amino}-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazolo[4,3-c]isoquinoline-7-carbaldehyde, and 10 ml of 5N aqueous HCl solution. The mixture is microwave-heated at 100° C. for 20 min and then poured into water and extracted with AcOEt. The organic phase is washed with saturated NaCl solution, dried over MgSO4, filtered and concentrated under RP. The product is purified by flash chromatography on silica gel (15-40 μm), eluting with a mixture of DCM and MeOH (95/5 by vol.). This gives 90 mg of 5-(2,6-difluorophenyl)-3-{[1-(ethylsulphonyl)piperidin-4-yl]amino}-1H-pyrazolo[4,3-c]isoquinoline-7-carbaldehyde in the form of a yellow foam. 1H NMR (500 MHz, DMSO-d6) δ ppm 1.23 (t, J=7.4 Hz, 3 H) 1.64 (m, 2 H) 2.10 (m, 2 H) 2.98 (m, 2H) 3.05 (q, J=7.4 Hz, 2 H) 3.62 (m, 2 H) 3.83 (m, 1 H) 6.18 (d, J=7.7 Hz, 1 H) 7.36 (t, J=7.8 Hz, 2 H) 7.71 (m, 1 H) 8.24 (broad s, 1 H) 8.34 (broad d, J=8.4 Hz, 1 H) 8.57 (d, J=8.4 Hz, 1 H) 10.11 (s, 1 H) 13.02 (s, 1 H). [M+H]+m/z=500.

Provenance & Evidence