1,8-Diazabicyclo(5.4.0)undec-7-ene → dimethylphosphinic acid 3-(1H-indol-2-yl)-1H-indazol-5-yl ester

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Reaction Steps

The dimethylphosphinic acid 3-(1H-indol-2-yl)-1H-indazol-5-yl ester compound is prepared according to procedure F using 230 mg of 3-(1H-indol-2-yl)-1H-indazol-5-ol (intermediate B) in solution with 245 mg of dimethylphosphinic acid 4-nitrophenyl ester in 5 ml of dichloromethane (stabilized with amylene) to which 170 μl of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in solution in 2 ml of dichloromethane are added. After stirring for 24 h at ambient temperature, the solvent is evaporated off and the crude is purified by preparative LC/MS. The crystals obtained after concentration of the fractions are washed with ethyl acetate and then with isopropyl ether. 129 mg of expected product are collected. Yield=43%.

Provenance & Evidence