6628-22-4

Basic information

• Product Name: 3,4-DIMETHYL-4,5-DIHYDRO-1H-PYRAZOL-5-ONE
• Synonyms: 3,4-DIMETHYL-4,5-DIHYDRO-1H-PYRAZOL-5-ONE;3,4-DIMETHYLPYRAZOLIN-5-ONE;3,4-dimethyl-5-pyrazolone;4,5-Dimethyl-1,2-dihydro-pyrazol-3-one;3,4-Dimethyl-2-pyrazolin-5-one;Einecs 229-608-6;2,4-Dihydro-4,5-dimethyl-3H-pyrazol-3-one;4,5-Dihydro-3,4-dimethyl-1H-pyrazol-5-one, 3,4-Dimethyl-2-pyrazolin-5-one
• CAS NO: 6628-22-4
• Molecular Formula: C₅H₈N₂O
• Molecular Weight: 112.13
• EINECS: 229-608-6
• Product Categories: Heterocyclic Compounds;Heterocycles
• Mol File: 6628-22-4.mol
• Article Data: 4

Chemical Properties

• Melting Point: 269-2710C
• Boiling Point: 307.5 °C at 760 mmHg
• Flash Point: 139.7 °C
• Appearance: white solid
• Density: 1.25
• Refractive Index: 1.579
• Storage Temp.: Refrigerator
• Solubility: DMSO, Methanol
• CAS DataBase Reference: 3,4-DIMETHYL-4,5-DIHYDRO-1H-PYRAZOL-5-ONE(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-DIMETHYL-4,5-DIHYDRO-1H-PYRAZOL-5-ONE(6628-22-4)
• EPA Substance Registry System: 3,4-DIMETHYL-4,5-DIHYDRO-1H-PYRAZOL-5-ONE(6628-22-4)

Safety Data

• Hazardous Substances Data: 6628-22-4(Hazardous Substances Data)

Usage

Chemical Properties

White Solid

Uses

3,4-Dimethyl-5-pyrazolone (cas# 6628-22-4) is a compound useful in organic synthesis.

InChI:InChI=1/C5H8N2O/c1-3-4(2)6-7-5(3)8/h3H,1-2H3,(H,7,8)

Upstream product

• 609-14-3 2-acetylpropanoic acid ethyl ester 
• 68654-22-8 9,10-dioxa-syn-(methyl,methyl)bimane 
• 1431522-64-3 4-(N-hydroxylamine)-4-methyl-5-methylpyrazolone 
• 68654-32-0 3,4-dimethyl-4-chloro-2-pyrazolin-5-one 
• 17094-21-2 2-methyl-acetoacetic acid methyl ester 

Downstream Products

• 68654-32-0 3,4-dimethyl-4-chloro-2-pyrazolin-5-one 
• 71418-44-5 monobromobimane 
• 68654-25-1 syn-4,6-bis(bromomethyl)-3,7-dimethyl-1,5-diazabicyclo<3.3.0>octa-3,6-diene-2,8-dione 
• 74235-78-2 9,10-dioxa-anti-(bromomethyl,methyl)(methyl,methyl)bimane 
• 220357-74-4 9,10-dioxa-syn-(methyl,phenyl)(methyl,methyl)bimane 
• 74235-89-5 9,10-dioxa-anti-(methyl,methyl)(methyl,phenyl)bimane 
• 74235-81-7 9,10-dioxa-syn-(bromomethyl, methyl)(methyl,phenyl)bimane 
• 68654-22-8 9,10-dioxa-syn-(methyl,methyl)bimane 
• 68654-23-9 3,4,7,8-tetramethyl-1,5-diazabicyclo<3.3.0>octa-3,7-diene-2,6-dione 

Relevant articles and documents

Catch-and-release of HNO with pyrazolones

A new and versatile class of HNO donors, the (hydroxylamino)pyrazolone (HAPY) series of HNO donors utilizing pyrazolone (PY) leaving groups, is described. HNO, the smallest N-based aldehyde equivalent, is used as a reagent along with a variety of PY compounds to synthesize the desired HAPY donors in what can be considered an N-selective HNO-aldol reaction in up to quantitative yields. The bimolecular rate constant of HNO with PY in pH 7.4 phosphate buffer at 37 °C can reach 8 × 105 M-1 s-1. In 1H NMR experiments, the HAPY compounds generate HNO quantitatively (trapped as a phosphine aza-ylide) with half-lives spanning 3 orders of magnitude (minutes to days) under physiologically relevant conditions. B3LYP/6-31G calculations confirm the energetically favorable reactions between HNO and the PY enol and enolate, whereas HNO release is expected to occur through the oxyanion (OHN-PY) of each HAPY compound. HNO has been shown to provide functional support to failing hearts.

Tautomerism-dependent ring construction of N-heterocyclic compounds from the reactions of 1-alkynyl fischer carbene complexes and substituted pyrazolinones

Four types of N-heterocyclic ring systems were successfully constructed from the reactions of 1-alkynyl Fischer carbene complexes (OC) 5M=C(OEt)C≡CPh (1) (M = Cr, W) and substituted pyrazolinones (2). Reactions of 1 with 3-methyl-2-pyrazolin-5-one (2a), 3-n-propyl-2- pyrazolin-5-one (2b), 3,4-dimethyl-2-pyrazolin-5-one (2c), 3,4-trimethylene-2- pyrazolin-5-one (2d), or 3,4-tetramethylene-2-pyrazolin-5-one (2e) generated three kinds of Fischer aminocarbene complexes (3-5), and reactions of 1 with phenyl-substituted pyrazolinones, i.e., 3-phenyl-2-pyrazolin-5-one (2f) and its tautomer 3-phenyl-3-pyrazolin-5-one (2g), gave Fischer alkoxycarbene complexes (6) as the major products and aminocarbene complexes of types 3-5 as the minor products. Multiple tautomerism of pyrazolinones is attributed to the versatile formation of N-heterocyclic Fischer carbene complexes. Oxidative demetalation of complexes 3-6 with pyridine N-oxide or m-chloroperoxybenzoic acid efficiently afforded organic carbonyl products, and thus, strongly fluorescent syn-mixed-bimanes were prepared. The present findings constitute an alternative new method to synthesize mixed bimanes and other novel N-heterocyclic compounds.