Chlorosulfonylation of the benzamidopyrazole (I) to give (II) was performed with neat chlorosulfonic acid at 0 C. Coupling of sulfonyl chloride (II) with the piperidinopropanoate (III) provided sulfonamide (IV). Finally, cyclization of (IV) with concomitant ester hydrolysis under basic conditions furnished the target pyrazolopyrimidine.