Cartazolate (SQ-65,396) is a

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhal ...

of the

pyrazolopyridine The pyrazolopyridines are a group of drugs investigated as anxiolytics which act as positive allosteric modulators of the GABAA receptor via the barbiturate binding site. They include the following compounds: * Cartazolate (SQ-65,396) * Eta ...

class. It acts as a GABA_A receptor

positive allosteric modulator In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds to ...

at the

barbiturate Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as ...

binding site In biochemistry and molecular biology, a binding site is a region on a macromolecule such as a protein that binds to another molecule with specificity. The binding partner of the macromolecule is often referred to as a ligand. Ligands may inclu ...

of the complex and has

anxiolytic An anxiolytic (; also antipanic or antianxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...

effects in animals. It is also known to act as an

adenosine Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside buildin ...

antagonist at the A₁ and A₂ subtypes and as a

phosphodiesterase inhibitor A phosphodiesterase inhibitor is a drug that blocks one or more of the five subtypes of the enzyme phosphodiesterase (PDE), thereby preventing the inactivation of the intracellular second messengers, cyclic adenosine monophosphate (cAMP) and cycl ...

. Cartazolate was tested in human

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

s and was found to be efficacious for

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil Turmoil may refer to: * ''Turmoil'' (1984 video game), a 1984 video game released by Bug-Byte * ''Turmoil'' (2016 video game), a 2016 indie oil tycoon video ...

but was never marketed. It was developed by a team at E.R. Squibb and Sons in the 1970s.

Synthesis

Condensation of aminopyrazole (1) with diethyl ethoxymethylenemalonate (2) gives the product of the addition-elimination (3). The product tautomerizes spontaneously to the hydroxypyridine (4). The hydroxyl group is then converted to the chloro-derivative by means of

phosphorus oxychloride Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosp ...

(5). Displacement of halogen by ''n''-butylamine gives the antidepressant compound cartazolate. Displacement of halogen by the basic nitrogen of

acetone hydrazone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscible wi ...

affords the antidepressant etazolate.

References

{{Phosphodiesterase inhibitors Adenosine receptor antagonists Amines Ethyl esters Carboxylate esters GABAA receptor positive allosteric modulators Phosphodiesterase inhibitors Pyrazolopyridines Butyl compounds

Synthesis

See also

References