1-Chloro-2-fluorobenzene → 6-Chloro-1-(2-chlorophenyl)-1'-methylspiro[indoline-3,4'-piperidine] maleate

Participants

Reaction Conditions

Reaction Steps

A mixture of 2.4 g of 6-chloro-1'-methylspiro[indoline-3,4'-piperidine], Example 23b, 0.5 g of sodium hydride (99% ) and 6 g of 2-chlorofluorobenzene in 25 ml of dimethylsulfoxide is stirred at 45° C. under nitrogen for 1 hour. Thereafter, the mixture is quenched with ice-water before being extracted thrice with ether. The combined ether extracts are successively washed with water, dried and concentrated under vacuum leaving a reddish oil. The oil is passed through an alumina column, ether eluant, and the purified oil, in ether, is converted to its maleic acid salt. The salt is recrystallized from an acetone-ether mixture to provide off-white platelets, mp 172°-173° C. of 6-chloro-1-(2-chlorophenyl)-1'-methylspiro[indoline-3,4'-piperidine] maleate.

Provenance & Evidence