Hydrochloric Acid → 5-Chloro-6-(2-chloro-4-fluorophenyl)-7-(4-methylpiperidin-1-yl)-3-methylmercapto-pyrazolo [2,3-a]pyrimidine

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Reaction Steps

With stirring, 1.06 g of aluminium trichloride were initially added to 1 g of 5-chloro-6-(2-chloro-4-fluorophenyl)-7-(4-methylpiperidin-1-yl)pyrazolo[2,3-a]pyrimidine, the preparation of which is described, for example, in WO 02/048151, in 50 ml of dichloromethane, and 0.99 g of methyl methylthiosulphonate was then added dropwise. After 15 h of stirring at room temperature, the mixture was poured into ice-water and hydrochloric acid was added. The organic phase was separated off, and the aqueous phase was extracted two more times with in each case 15 ml of ethyl acetate. The combined organic phases were dried with sodium sulphate, and the solvent was removed under reduced pressure. The residue was chromatographed on silica gel using cyclohexane/ethyl acetate 4:1. This gave 0.65 g of an orange oil, logPs=5.73.

Provenance & Evidence