Pazinaclone
Pazinaclone (DN-2327) is a sedative and anxiolytic drug in the cyclopyrrolone family of drugs. Some other cyclopyrrolone drugs include zopiclone and eszopiclone.
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| Formula | C25H23ClN4O4 |
| Molar mass | 478.928 g/mol g·mol−1 |
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Pazinaclone has a very similar pharmacological profile to the benzodiazepines including sedative and anxiolytic properties, but with less amnestic effects,[1] and at low doses it is a relatively selective anxiolytic, with sedative effects only appearing at higher doses.[2]
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.[3]
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-butyl(triphenylphosphoranylidene)acetate 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-azaspiro[4.5]decane results in formation of the corresponding amide, pazinaclone.
See also
References
- Wada T, Fukuda N. Effect of a new anxiolytic, DN-2327, on learning and memory in rats. Pharmacology Biochemistry and Behavior. 1992 Mar;41(3):573-9.
- Suzuki M, Uchiumi M, Murasaki M. A comparative study of the psychological effects of DN-2327, a partial benzodiazepine agonist, and alprazolam. Psychopharmacology. 1995 Oct;121(4):442-50.
- Atack JR. The benzodiazepine binding site of GABA(A) receptors as a target for the development of novel anxiolytics. Expert Opinion on Investigational Drugs. 2005 May;14(5):601-18.
