A mixture of 2,2,2-trifluoro-1-(1H-indazol-5-yl)-1-(1-methyl-1H-indol-3-yl)ethanol (0.165 mmol) and isopropyl chloroformate (0.49 mmol from a 1.0 M solution in toluene) in 1 mL of pyridine was heated at 85° C. for 10 hours, cooled to room temperature, and diluted with ether and water. The organic layer was washed with water and brine and dried over magnesium sulfate. The volatiles were concentrated in vacuo and the residue purified by flash silica gel chromatography using 33% ethyl acetate in hexanes. The product-rich fractions were concentrated in vacuo to afford 0.069 mmol of the desired compound, m.p. 105° C.-106° C.
