Tetrabenazine, synthesis

Tetrabenazine, 350 Tetracaine, 10 Tetracycline, 212, 213 A -Tetrahydrocannabinol, 394 Tetrahydropyrimidines, synthesis, 266... 

The antidiarrhoeal drug ipecac, which was introduced into Europe from Brazil in 1658, contains the amoebicidal alkaloids emetine (12) and cephaeline. Emetine remained the major remedy for amoebic dysentery and amoebic hepatitis for many years. Cephaeline is less active and more toxic. ( j-2-Dehydroemetine, which is made by synthesis, is equiactive with (—)-emetine and less toxic, but other chemical modification has not yielded better amoebicides. From investigations of synthetic routes to the benzoquinolizine moiety the tranquilizer tetrabenazine (13a) was discovered. The very similar compound benzquinamide (13b) is also a tranquilizer and antiemetic. 

Tetrabenazine or 2-oxo-3-isobutyl-9,10-dimethoxyhexahydrobenzo-[a]quinolizine (LVI) (229), which has apparently emanated from work related to the synthesis of emetine, has obtained much attention recently. In spite of the absence of an indole ring system, it seems to possess sedative reserpine-like activity. Tetrabenazine has been pharmacologically studied in great detail (230). 

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