trans-Crotonyl chloride → HCID 10246368, compound

Participants

Reaction Conditions

Reaction Steps

0.45 cm3 of predistilled crotonyl chloride is added to 1 g of 6-chloro-1-[(1,1-dimethylethoxy)carbonyl]-1H-indazole-3-amine described previously, in 40 cm3 of dichloromethane and 1.05 cm3 of triethylamine. The mixture is stirred at about 19° C. for 16 hours. The medium is then concentrated under reduced pressure (20 kPa; 40° C.). The residue is taken up in 100 cm3 of ethyl acetate and 50 cm3 of distilled water. The organic phase is then washed with 50 cm3 of saturated aqueous sodium chloride solution. The resulting solution is dried over magnesium sulphate, filtered through a sinter funnel and then evaporated under the conditions already described previously. The residue is purified by chromatography under an argon pressure of 50 kPa, on silica gel (particle size 40-60 μm; diameter 3 cm), eluting with a cyclohexane/ethyl acetate mixture (90/10 by volume) and collecting 15 cm3 fractions. The fractions containing the expected product are combined and then evaporated under reduced pressure (2 kPa; 40° C.). After drying (90 Pa; 45° C.), 120 mg of N-(6-chloro-1-[(1,1-dimethylethoxy)carbonyl]-1H-indazol-3-yl)-3-butenamide are obtained in the form of a yellow solid.

Provenance & Evidence