Hydrochloric Acid → 3H-spiro[2-benzofuran-1,4'-piperidine]

Participants

Reaction Conditions

Reaction Steps

A solution of lithium aluminum hydride (7.5 mL 1M in ether) diluted with 35 mL of tetrahydrofuran was cooled to 0° C. and added to a suspension of 3-oxospiro[isobenzofuran-1(3H),4'-piperidine] (0.38 g) in 40 mL of anhydrous tetrahydrofuran containing boron trifluoride etherate (6.9 mL). The reaction mixture was allowed to warm to room temperature and then refluxed for 3 hours. At the end of this period, the reaction mixture was cooled in ice and treated with 5% HCl (8 mL) followed by water (8 mL). After concentrating under reduced pressure, the reaction mixture was treated with concentrated HCl (8 mL) and heated to reflux, cooled to room temperature, the pH was adjusted to 5 by adding sodium hydroxide solution and extracted with ether. The aqueous layer was made basic (pH 11) with sodium hydroxide and extracted with two portions of dichloromethane. The dichloromethane layer was dried and evaporated to afford the named product (0.28 g) which was used in the next step without further purification; MS: 190; NMR: 7-1.1.9 (m, 4), 2.9-3.1 (m, 4), 5.1 (s, 2), 7.1-7.3 (m, 4).

Provenance & Evidence