Dimethylamine → HCID 9796539, compound

Participants

Reaction Conditions

Reaction Steps

A solution of cis-3-(3′,4′-dichlorophenyl)indan-1-o1(22.7 g, 0.081 mol) and triethylamine (45 mL, 0.325 mole) in THF (350 mL) was stirred (overhead stirring) under an inert atmosphere while maintaining a solution temperature of −15° C. In a separate flask under inert atmosphere, a solution of methanesulfonyl chloride (12.6 mL, 0.162 mol) in the THF (150 mL) was cooed to −60° C., then added slowly to the solution of cis-3-(3′,4′-dichlorophenyl) indan-1-o1, maintaining the temperature of the reaction mixture below 0° C. After addition was complete, the reaction mixture was stirred for 10 min. at 0° C., then purged with dimethylamine gas (56 g, 1.21 mol). The reaction mixture was allowed to warm to room temperature and stirred for 5 h. The reaction was monitored by TLC against an authentic sample of cis-3-(3′,4′-dichlorophenyl)indan-1-o1 and against an authentic sample of trans-1-(N,N-dimethylamino) 3-(3′,4′-dichlorophenyl)indan. When the reaction was complete, THF was removed under reduced pressure, and the mixture was extracted with ethyl acetate (250 mL). The ethyl acetate layer was removed, and the aqueous layer was extracted with ethyl acetate (2×100 mL). The combined ethyl acetate layers were washed with brine (2×100 mL) and dried over anhydrous sodium sulfate. The ethyl acetate solution was concentrated to give 26 g of 1-(N,N-dimethylamino)-3-(3′,4′-dichlorophenyl)indan as a brown oil. The cis:trans isomeric ratio of the crude amine was 5:95 as determined by HPLC. The crude amine (26 g) was stirred with ethyl acetate (5 mL) for 10 min. After a solid started to form, heptane (45 mL) was added. The mixture was stirred for 1 hour at 15° C., then the precipitated product was collected by filtration, then washed with 40 mL of heptane. The product was dried under high vacuum to give 14 g of product (56%, first crop). The mother liquor was evaporated to an oil. A solution (15 mL) of 10% ethyl acetate in heptane was added to the oil and stirred for 1 hour at 15° C. The precipitated product was collected by filtration, then washed with 20 mL of heptane. The solid was dried under vacuum to give 5.2 g (21%, second crop). HPLC analysis indicated that the two crops contained the same ratio (0.6%) of the undesired cis isomer. The combined crops (19.2 g) were again stirred with a solution (40 mL) of 10% ethyl acetate in heptane for 1 hour at 15° C. The precipitated product was collected by filtration, then washed with 30 mL of heptane. The product was dried under high vacuum to give 15 g (60%) of 1-(N,N-dimethylamino) 3-(3′,4′-dichlorophenyl) indan. Only 0.2% of the undesired cis isomer was detected by HPLC.

Provenance & Evidence