Phenylacetyl chloride → 2,3-Dihydro-1'-(phenylacetyl)spiro[benzofuran-2,3'-pyrrolidine]

Participants

Reaction Steps

A solution of 4.0 g of phenylacetyl chloride in 10 ml of chloroform is added dropwise to a stirred solution of 4.0 g of 2,3-dihydrospiro[benzofuran-2,3'-pyrrolidine], free base of Example 8, and 3 ml of triethylamine in 40 ml of chloroform. After total addition, the reaction mixture is stirred successively at ambient temperature for 18 hours and at reflux for 3 hours and then permitted to cool to ambient temperature before being poured into 100 ml of water. The organic layer is collected and then washed sequentially with dilute acid, dilute base, a saturated sodium chloride solution and dried. Thereafter, the solvent is evaporated off, leaving a dark oil which is chromatographed through a silica gel column with a 5% methyl alcohol in chloroform eluant, leaving a light yellow oil. This oil is triturated with boiling hexane, the triturant is decanted and allowed to cool, which causes a precipitate to appear. The precipitate is collected and recrystallized twice from hexane to give the pure product, 2,3-dihydro-1'-(phenylacetyl)spiro[benzofuran-2,3'-pyrrolidine], mp 98°-99° C.

Provenance & Evidence