Ethyl Acetate → HCID 53482858, compound

Participants

Reaction Steps

A solution of 3,4-dihydropyrazino[1,2-b]indazol-1(2H)-one (375 mg; 2.0 mmol) in a mixture of tetrahydrofuran:dimethylformamide (DMF) in a ratio of 1:1 (4 ml) was added drop wise to a suspension of NaH 55% in mineral oil (104 mg; 2.4 mmol) in anhydrous tetrahydrofuran (THF), kept stirred at room temperature under argon atmosphere. The mixture was kept under stirring at the same temperature under inert atmosphere for 1 h; then, a solution of 1-(3-chloropropyl)-4-phenylpiperidine (4.4 g; 0.015 mol) in DMF (25 ml) was slowly added. Once the additions were over, the mixture was heated at the reflux temperature for 6 h. The reaction was then stopped by cooling the mixture to room temperature and by adding ethyl acetate (10 ml). The mixture was then filtered through a silica gel pad, then the solvent was removed by evaporation at reduced pressure. The residue was purified by flash chromatography on silica gel, using a mixture of chloroform:methanol in a ratio of 9:1 as eluent. The product thus purified was dissolved in a mixture of diethyl ether:ethanol in a ratio of 10:1 (10 ml) and processed at room temperature with 3M HCl in ethanol (0.33 ml). The solid thus formed was filtered and crystallized from a mixture of isopropanol:diisopropyl ether in a ratio 1:1. Thus, 197 mg of 2-[3-(4-phenylpiperidin-1-yl)propyl]-3,4-dihydropyrazino[1,2-b]indazol-1(2H)-one hydrochloride were obtained.

Provenance & Evidence