No abstract

No abstract

No abstract

(−)-3-(2-Benzothienyl)-8-H-8-azabicyclo[3,2,1]oct-2-ene acetate, NS9544 acetate, is a candidate drug intended to treat pain and other CNS disorders. In the synthetic route tropinone was enantioselective deprotonated with a chiral lithium amide derived from [R-(R*,R*)]-bis(α-methylbenzyl)amine hydrochloride. The formed enolate was trapped as triflate and coupled with benzo[b]thiophene-2-boronic acid under Suzuki conditions. To further enhance the enantiomeric purity crystallisation with l-(+)-tartaric acid was performed. Finally N-demethylation with trichloroethylchloroformate followed by treatment with acetic acid afforded NS9544 as the acetate salt with high enantiomeric purity.