Boron tribromide → 1-(3-amino-7-fluoro-6-hydroxy-1H-indazol-5-yl)-3-(3-fluorobenzyl)urea

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Reaction Steps

70 mg of 1-(3-amino-6-ethoxy-7-fluoro-1H-indazol-5-yl)-3-(3-fluorobenzyl)urea are suspended in 2 ml of dichloromethane, and 105 μl of BBr3 are added. After 24 hours at RT, the mixture is carefully quenched using 1 ml of methanol and evaporated to dryness. Purification by chromatography on RP-18 silica gel (eluent:acetonitrile/water) gives 15 mg of 1-(3-amino-7-fluoro-6-hydroxy-1H-indazol-5-yl)-3-(3-fluorobenzyl)urea (“A 15”) as a virtually colourless solid (22%), MS-FAB (M+H+)=334;

Provenance & Evidence