Pyrazolopyrimidine

Last updated
Pyrazolo[1,5-a]pyrimidine
Pyrazolopyrimidine.svg
Names
Preferred IUPAC name
Pyrazolo[1,5-a]pyrimidine
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.227.461 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C6H5N3/c1-3-7-6-2-4-8-9(6)5-1/h1-5H
    Key: LDIJKUBTLZTFRG-UHFFFAOYSA-N
  • InChI=1/C6H5N3/c1-3-7-6-2-4-8-9(6)5-1/h1-5H
    Key: LDIJKUBTLZTFRG-UHFFFAOYAL
  • n1cccn2nccc12
Properties
C6H5N3
Molar mass 119.127 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Pyrazolopyrimidines are a series of isomeric heterocyclic chemical compounds with the molecular formula C6H5N3. [1] They form the central core of a variety of more complex chemical compounds including some pharmaceuticals and pesticides.

Contents

Pharmaceuticals

One isomer of pyrazolopyrimidines, known as pyrazolo[1,5-a]pyrimidine, is the basis for a class of sedative and anxiolytic drugs related (in terms of their effect) to benzodiazepines.

Most of the drugs from this class marketed to date are intended to induce sleep, and are prescribed for people suffering insomnia, however some newer compounds produce anxiolytic effects with relatively little sedation, and are being developed for use as non-sedating anti-anxiety drugs.

They include:

As they are not chemically related to the benzodiazepines despite their similar effect, such drugs—as well as the imidazopyridines and cyclopyrrones—are sometimes grouped together and referred to as "nonbenzodiazepines".

Zaleplon Zaleplon skeletal.svg
Zaleplon

Pesticides

A related use is in pyrazolopyrimidine organothiophosphate pesticides including chlorprazophos (insecticide) and pyrazophos (fungicide, insecticide).

Pyrazophos Pyrazophos.svg
Pyrazophos

See also

Related Research Articles

Flunitrazepam Benzodiazepine sedative

Flunitrazepam, also known as Rohypnol among other names, is a benzodiazepine used to treat severe insomnia and assist with anesthesia. As with other hypnotics, flunitrazepam has been advised to be prescribed only for short-term use or by those with chronic insomnia on an occasional basis.

Hypnotic Drug whose use induces sleep

Hypnotic, or soporific drugs, commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to induce sleep and to treat insomnia (sleeplessness).

A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but the majority of them affect the neurotransmitter gamma-aminobutyric acid (GABA). In spite of the fact that each sedative acts in its own way, most produce relaxing effects by increasing GABA activity.

Triazolam Benzodiazepine class medication

Triazolam, sold under the brand name Halcion among others, is a central nervous system (CNS) depressant tranquilizer of the triazolobenzodiazepine (TBZD) class, which are benzodiazepine (BZD) derivatives. It possesses pharmacological properties similar to those of other benzodiazepines, but it is generally only used as a sedative to treat severe insomnia. In addition to the hypnotic properties, triazolam's amnesic, anxiolytic, sedative, anticonvulsant, and muscle relaxant properties are pronounced, as well.

Imidazopyridine Class of compounds

An imidazopyridine is a nitrogen containing heterocycle that is also a class of drugs that contain this same chemical substructure. In general, they are GABAA receptor agonists, however recently proton pump inhibitors, aromatase inhibitors, NSAIDs and other classes of drugs in this class have been developed as well. Despite usually being similar to them in effect, they are not chemically related to benzodiazepines. As such, GABAA-agonizing imidazopyridines, pyrazolopyrimidines, and cyclopyrrones are sometimes grouped together and referred to as "nonbenzodiazepines." Imidazopyridines include:

Zopiclone Hypnotic medication

Zopiclone, sold under the brand name Imovane among others, is a nonbenzodiazepine used to treat difficulty sleeping. Zopiclone is molecularly distinct from benzodiazepine drugs and is classed as a cyclopyrrolone. However, zopiclone increases the normal transmission of the neurotransmitter gamma-aminobutyric acid (GABA) in the central nervous system, via modulating GABAA receptors similarly to the way benzodiazepine drugs do.

Flurazepam Hypnotic medication

Flurazepam is a drug which is a benzodiazepine derivative. It possesses anxiolytic, anticonvulsant, hypnotic, sedative and skeletal muscle relaxant properties. It produces a metabolite with a long half-life, which may stay in the bloodstream for days. Flurazepam was patented in 1968 and came into medical use the same year. Flurazepam, developed by Roche Pharmaceuticals was one of the first benzo hypnotics to be marketed.

Zaleplon Medication

Zaleplon, sold under the brand names Sonata among others, is a sedative-hypnotic, used to treat insomnia. It is a nonbenzodiazepine hypnotic from the pyrazolopyrimidine class.

Nonbenzodiazepine Class of psychoactive drugs

Nonbenzodiazepines, sometimes referred to colloquially as Z-drugs, are a class of psychoactive drugs that are very benzodiazepine-like in nature. They are used in the treatment of sleep problems.

Estazolam Tranquilizer

Estazolam, sold under the brand name Prosom among others, is a tranquilizer medication of the triazolobenzodiazepine (TBZD) class, which are benzodiazepines (BZDs) fused with a triazole ring. It possesses anxiolytic, anticonvulsant, hypnotic, sedative and skeletal muscle relaxant properties. Estazolam is an intermediate-acting oral benzodiazepine. It is used for short-term treatment of insomnia.

Alpidem Chemical compound

Alpidem (Ananxyl) is an anxiolytic drug from the imidazopyridine family, related to the more well known sleeping medication zolpidem. Unlike zolpidem however, alpidem does not produce sedative effects at normal doses, and is instead used specifically for the treatment of anxiety.

Pagoclone

Pagoclone is an anxiolytic agent from the cyclopyrrolone family, related to better-known drugs such as the sleeping medication zopiclone. It was synthesized by a French team working for Rhone-Poulenc & Rorer S.A. Pagoclone belongs to the class of nonbenzodiazepines, which have similar effects to the older benzodiazepine group, but with quite different chemical structures. It was never commercialised.

Panadiplon

Panadiplon (U-78875) is an anxiolytic drug with a novel chemical structure that is not closely related to other drugs of this type. It has a similar pharmacological profile to the benzodiazepine family of drugs, but with mainly anxiolytic properties and relatively little sedative or amnestic effect, and so is classified as a nonbenzodiazepine anxiolytic.

SL651498 Chemical compound

SL651498 is an anxiolytic and anticonvulsant drug used in scientific research, with a chemical structure most closely related to β-carboline derivatives such as abecarnil and gedocarnil. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.

RWJ-51204 Chemical compound

RWJ-51204 is an anxiolytic drug used in scientific research. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.

Y-23684

Y-23684 is an anxiolytic drug with a novel chemical structure, which is used in scientific research. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.

SX-3228

SX-3228 is a sedative and hypnotic drug used in scientific research. It has similar effects to sedative-hypnotic benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine hypnotic.

U-90042

U-90042 is a sedative and hypnotic drug used in scientific research. It has similar effects to sedative-hypnotic benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine hypnotic.

TP-13

TP-13 is an anxiolytic drug with a novel chemical structure, which is used in scientific research. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic. It is a subtype-selective partial agonist at GABAA receptors, binding selectively to GABAA receptor complexes bearing α2 and α3 subunits. It has modest anticonvulsant activity although less than that of diazepam, and its main effect is likely to be selective anxiolytic action, as seen with other related α2/3-preferring agonists such as L-838,417.

Cinazepam Chemical compound

Cinazepam is an atypical benzodiazepine derivative. It produces pronounced hypnotic, sedative, and anxiolytic effects with minimal myorelaxant side effects. In addition, unlike many other benzodiazepine and nonbenzodiazepine hypnotics such as diazepam, flunitrazepam, and zopiclone, cinazepam does not violate sleep architecture, and the continuity of slow-wave sleep and REM sleep are proportionally increased. As such, cinazepam produces a sleep state close to physiological, and for that reason, may be advantageous compared to other, related drugs in the treatment of insomnia and other sleep disorders.

References

  1. "Note that according to other sources, the structure is different, and the sum formula is C5H4N4: see pyrazolopyrimidine on". ChemSpider. Retrieved 2018-11-07.