Water → 2,3-Dihydro-3,3-dimethyl-2-piperidinobenzofuran-5-yl methanesulphonate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 2,3-dihydro-3,3-dimethyl-5-hydroxy-2-piperidino-benzofuran (640 parts) in dry pyridine (1000 parts) at 5-10° C. was added methanesulphonyl chloride (370 parts) over 1 hour. The mixture was stirred for a further 5 hours at about 10° C., then poured into water. The precipitated gum was washed with water (3 × 200 parts) by decantation, then triturated with ethanol (500 parts) when it set to a crystalline mass which was broken up, filtered, and the residue of crude ester was washed with aqueous ethanol (2:1) and sucked dry. Drying at 35° C. in vacuo over phosphoric oxide gave 2,3-dihydro-3,3-dimethyl-2-piperidinobenzofuran-5-yl methanesulphonate (660 parts, 78%) m.p. 97°-8° C.

Provenance & Evidence