Hydrochloric Acid → HCID 58551183, compound

Participants

Reaction Conditions

Reaction Steps

To tert-butyl 3-(diethoxymethyl)-4-oxo-spiro[chromane-2,4′-piperidine]-1′-carboxylate (15.1 g, 35.9 mmol) and hydrazine (1.35 mL, 43.1 mmol) in EtOH (120 mL) was added hydrochloric acid (900 μL of 4.0 M in dioxanes, 3.6 mmol). The mixture was heated at 60° C. for 2 h before it was cooled and the solvent was evaporated. The residue was purified by silica gel chromatography eluting with 0-100% ethyl acetate in hexanes to give tert-butyl spiro[1H-chromeno[4,3-c]pyrazole-4,4′-piperidine]-1′-carboxylate (8.76 g, 71%). ESI-MS m/z calc. 341.2. found 342.3 (M+1)+; Retention time: 1.69 minutes (3 min run).

Provenance & Evidence