81945-73-5

Basic information

• Product Name: 1-hydroxy-1H-pyrazole
• Synonyms: 1-hydroxy-1H-pyrazole;1H-Pyrazol-1-ol;1H-Pyrazole, 1-hydroxy-;Einecs 279-854-3;1-hydroxy-1,2-diazole;1-Hydroxypyrazole;N-Hydroxypyrazole;Pyrazol-1-ol
• CAS NO: 81945-73-5
• Molecular Formula: C₃H₄N₂O
• Molecular Weight: 84.07666
• EINECS: 279-854-3
• Mol File: 81945-73-5.mol

Chemical Properties

• Melting Point: 74℃
• Boiling Point: 242.3°Cat760mmHg
• Flash Point: 100.3°C
• Appearance: /
• Density: 1.3g/cm³
• Storage Temp.: Sealed in dry,Room Temperature
• PKA: 9.38±0.58(Predicted)
• CAS DataBase Reference: 1-hydroxy-1H-pyrazole(CAS DataBase Reference)
• NIST Chemistry Reference: 1-hydroxy-1H-pyrazole(81945-73-5)
• EPA Substance Registry System: 1-hydroxy-1H-pyrazole(81945-73-5)

Safety Data

• Hazardous Substances Data: 81945-73-5(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Industry:
1-hydroxy-1H-pyrazole is used as a key intermediate in the synthesis of pharmaceutical compounds for various therapeutic applications. Its ability to form multidentate ligands allows for the creation of molecules with enhanced binding properties and improved pharmacological effects.
Used in Chemical Research:
1-hydroxy-1H-pyrazole is also utilized in chemical research for the development of new synthetic routes and methodologies. Its unique structure and reactivity make it a valuable tool for exploring novel chemical reactions and the synthesis of complex organic molecules.

Upstream product

• 288-13-1 NH-pyrazole 
• 1383843-59-1 3,4,5-trinitro-1H-pyrazol-1-ol 
• 145162-47-6 1-benzyl-1H-pyrazole-2-oxide 
• 100159-47-5 1-(benzyloxy)pyrazole 
• 71989-66-7 4-bromo-3,5-dimethyl-1-hydroxypyrazole 2-oxide 

Downstream Products

• 142346-90-5 N-2-[4-(1,1-dimethylethoxy)phenoxy]ethoxypyrazole 
• 548765-36-2 methyl-phenyl-carbamic acid pyrazol-1-yl ester 
• 548767-62-0 Morpholine-4-carboxylic acid pyrazol-1-yl ester 
• 548767-67-5 4-Phenyl-piperazine-1-carboxylic acid pyrazol-1-yl ester 
• 784190-13-2 5-bromo-1-(2,6-difluorobenzyl)-1H-pyrazole 
• 445411-86-9 2-(pyrazol-1-yloxy)benzonitrile 
• 145162-48-7 2-(p-methoxybenzyl)pyrazole 1-oxide 
• 145162-47-6 1-benzyl-1H-pyrazole-2-oxide 
• 100159-47-5 1-(benzyloxy)pyrazole 

Relevant articles and documents

Synthesis and properties of 3,4,5-trinitropyrazole-1-ol and its energetic salts

3,4,5-Trinitropyrazole-1-ol and its nitrogen-rich salts were synthesized and well characterized by 1H, 13C NMR (some with 15N NMR), and IR spectroscopy, and by elemental analysis. Additionally, the structures of the ammoni

1H-QUINAZ0LINE-2,4-DIONES AND THEIR USE AS AMPA-RECEPTOR LIGANDS

The present invention relates to l H-Quinazoline-2,4-diones of formula (I) wherein R1 and R2 are as defined in the specification, their preparation, their use as AMPA-receptor ligands, in particular for the treatment of epilepsy or schizophrenia, and pharmaceutical compositions containing them. Further, intermediates for the manufacture of compounds of formula (I) and combinations comprising compounds of formula (I) are disclosed.

AZOLE INHIBITORS OF CYTOKINE PRODUCTION

Compounds having the formula are useful for treating diseases that are prevented by or ameliorated with Interleukin-2, Interleukin-4, or Interleukin-5 production inhibitors.

Preparation of 1-hydroxypyrazoles and 1-hydroxy-1,2,3-triazoles by dealkylation of pyrazole and triazole N-oxides

1-Hydroxypyrazoles were obtained from 2-benzylpyrazole 1-oxides by debenzylation with iodotrimethylsilane. 1-Hydroxy-1,2,3-triazoles were achieved from 2-benzyltriazole 1-oxides by debenzylation effected with conc. hydrobromic acid or from 2- or 3-p-methoxybenzyltriazole 1-oxides by de-p methoxybenzylation accomplished by treatment with conc. sulfuric acid. 1-Methoxy-1,2,3-triazole was obtained by de-p-methoxybenzylation of 1-methoxy-3-p-methoxybenzyl-1,2,3-triazolium tetrafluoroborate accomplished by treatment with conc. sulfuric acid. 1-Hydroxypyrazole was selectively N-benzylated in absence of base to give 2-benzylpyrazole 1-oxide which, upon selective substitution at the 3-position and subsequent debenzylation, produced 3-substituted 1-hydroxypyrazole. Acta Chemika Scandinavica 1996.

Synthesis of 5-Substituted 1-Hydroxypyrazoles through Directed Lithiation of 1-(Benzyloxy)pyrazole

1-Hydroxypyrazoles have been converted to 1-(benzyloxy), , , and (silyloxy)pyrazoles. 1-(Benzyloxy)pyrazole was lithiated selectively in the 5-position.Subsequent reaction with electrophiles gives rise to 1-(benzyloxy)pyrazole with carbon, halogen, silicon, sulfur, or tin substituents at the 5-position. 1-(Benzyloxy)pyrazoles could be debenzylated by hydrogen bromide or hydrogenolysis producing 5-substituted 1-hydroxypyrazoles in high overall yield.

Preparation of N-Hydroxyazoles by Oxidation of Azoles

Azoles without N-substituents are oxidized with per-acids or perborate to the corresponding N-hydroxy substituted azoles. 1,2,4-Triazole and tetrazole produce two isomers separated through their O-benzyl derivatives.Imidazole and 1,2,3- and 1,2,4-triazole can be di-oxygenated in low yields.N-Hydroxypyrazole is deoxygenated by per-acid.

A Facile Synthesis of 1-Hydroxypyrazole by Oxidation of Pyrazole

The oxidation of sodium pyrazolate with dibenzoyl peroxide is the first direct route to 1-hydroxypyrazole (2a).The reaction may be also applied to substituted pyrazoles. - Keyword: 1-Hydroxypyrazoles

Preparation of N-hydroxypyrazoles

N-hydroxypyrazoles of the general formula I STR1 where R1, R2 and R3 may be identical or different and are each hydrogen or halogen, are prepared by a process in which a pyrazole of the general formula II STR2 where R1, R2 and R3 have the meanings stated for formula I, is reacted with an aliphatic or aromatic peroxocarboxylic acid, preferably in the presence of from 0 to 15 moles of an alkali metal hydroxide, alkaline earth metal hydroxide, alkali meteal carbonate or alkaline earth metal carbonate in such a way that the reaction temperature is from -5° C. to 60°C. The reaction can be carried out in water as a solvent or in a 2-phase system consisting of water and an inert organic solvent which is poorly miscible with water, in the presence or absence of a suitable phase transfer catalyst. The peroxocarboxylic acid can be prepared in the reaction mixture before the reaction from H2 O2 and an acyl halide or a carboxylic anhydride or can be used in the form of an alkali metal salt or alkaline earth metal salt.

1-Hydroxypyrazole

1-Hydroxypyrazole and a process for its preparation by conversion of isoxazolineazoxy compounds at 140°-600° C. The end products obtainable by the process of the invention are valuable starting materials for the preparation of dyes, crop protection agents and drugs.