1,4-Dioxane hydrochloride → 1-(3-amino-6-ethoxy-7-fluoro-1H-indazol-5-yl)-3-(3-fluorobenzyl)urea

Participants

Reaction Steps

4.4 250 mg of tert-butyl 3-tert-butoxycarbonylamino-6-ethoxy-7-fluoro-5-[3-(3-fluorobenzyl)ureido]indazole-1-carboxylate (4.5 mmol) are stirred for 16 hours with 5 ml of HCl/dioxane (4 M). The batch is concentrated and evaporated three times with 20 ml of toluene each time in a rotary evaporator. The residue is purified by column chromatography on silica gel (eluent:ethyl acetate:methanol 9:1). Evaporation of the corresponding fractions gives 50 mg of 1-(3-amino-6-ethoxy-7-fluoro-1H-indazol-5-yl)-3-(3-fluorobenzyl)urea (“A14”) (31%), MS-FAB (M+H+)=362.

Provenance & Evidence