Water → HCID 70456182, compound

Participants

Reaction Steps

In a three necked flask equipped with a thermometer, a stirrer and a reflux condenser having Widmer-type water trap filled with Molecular Sieves are placed 4-oxo-5-bromo-1-benzenesulfonyl-4,5,6,7-tetrahydroindole (100 parts), 3-chloro-1,2-propanediol (311 parts), p-toluenesulfonic acid monohydrate (3 parts) and toluene (4500 parts), and the mixture is refluxed for 7 hours 20 minutes while drying the refluxing azeotropic mixture. After cooling, the reaction mixture is adjusted to pH 9 with 2.5N aqueous sodium hydroxide with stirring, and the formed toluene layer is separated. The water layer is washed with benzene (200 parts). Toluene layer and benzene washing are combined, washed twice with water (500 parts) and dried over anhydrous sodium sulfate (500 parts). The drying agent is filtered off, and the filtrate is concentrated under reduced pressure. The obtained residue (143 parts) is dissolved in benzene (300 parts), stirred with active charcoal (50 parts) for 30 minutes and filtered through a filter-bed of siliceous earth. The filtrate is concentrated under reduced pressure, and stirring of resulted residue with a small amount of ether and hexane affords amorphous powder. This is collected by filtration, washed with a mixture of ether and hexane, and dried to give 4'-chloromethyl-5-bromo-1-benzenesulfonyl-4,5,6,7-tetrahydroindole-4-spiro-2'-[1,3]-dioxolane diastereomer mixture (122 parts) in 97% yield.

Provenance & Evidence