Pazinaclone


Pazinaclone is a sedative and anxiolytic drug in the cyclopyrrolone family of drugs. Some other cyclopyrrolone drugs include zopiclone and eszopiclone.
Pazinaclone has a very similar pharmacological profile to the benzodiazepines including sedative and anxiolytic properties, but with less amnestic effects, and at low doses it is a relatively selective anxiolytic, with sedative effects only appearing at higher doses.
Pazinaclone produces its sedative and anxiolytic effects by acting as a partial agonist at GABAA benzodiazepine receptors, although pazinaclone is more subtype-selective than most benzodiazepines.

Synthesis

Reaction of 2-amino-7-chloro-1,8-naphthyridine with phthalic anhydride leads to the corresponding phthalimide. Selective reduction of one of the imide carbonyl groups in essence converts that to an aldehyde. Condensation with tert-butylacetate gives the Wittig product.
The carboxylic acid is then treated with diethyl cyanophosphonate to convert that to an activated acid cyanide; reaction with 1,4-dioxa-8-azaspirodecane results in formation of the corresponding amide, pazinaclone.