Hydrazine hydrate (1:1) → benzyl 6-isopropyl-6,7-dihydro-1H-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate

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Reaction Steps

5-(4-Chlorophenylsulfonyl)-6-(3-fluorophenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine (Enantiomers A and B) Benzyl 2-(3-fluorophenyl)-4-oxopiperidine-1-carboxylate, prepared as described for compound 67 in Example 3 using (3-fluorophenyl)magnesium bromide, was formylated and treated with hydrazine hydrate as described for compound 50 in Example 1 to give benzyl 6-isopropyl-6,7-dihydro-1H-pyrazolo[4,3-c]pyridine-5(4H)-carboxylate. This compound was then deprotected and treated with 4-chlorophenylsulfonyl chloride followed by NaOH as described for compound 52 in Example 1. The enantiomers were separated using HPLC Method [2].

Provenance & Evidence