91798-68-4

Basic information

• Product Name: 3-Buten-2-one, 4-(1H-pyrazol-1-yl)-, (E)- (9CI)
• Synonyms: 3-Buten-2-one, 4-(1H-pyrazol-1-yl)-, (E)- (9CI)
• CAS NO: 91798-68-4
• Molecular Formula: C₇H₈N₂O
• Molecular Weight: 136.15122
• Product Categories: ACETYLGROUP
• Mol File: 91798-68-4.mol
• Article Data: 3

Chemical Properties

• Appearance: /
• CAS DataBase Reference: 3-Buten-2-one, 4-(1H-pyrazol-1-yl)-, (E)- (9CI)(CAS DataBase Reference)
• NIST Chemistry Reference: 3-Buten-2-one, 4-(1H-pyrazol-1-yl)-, (E)- (9CI)(91798-68-4)
• EPA Substance Registry System: 3-Buten-2-one, 4-(1H-pyrazol-1-yl)-, (E)- (9CI)(91798-68-4)

Safety Data

• Hazardous Substances Data: 91798-68-4(Hazardous Substances Data)

Upstream product

• 288-13-1 NH-pyrazole 
• 51731-17-0 trans-4-methoxy-3-buten-2-one 
• 91798-67-3 trans-4-(phenylsulfinyl)-3-buten-2-one 
• 1423-60-5 methyl ethynyl ketone 
• 4643-20-3 (E)-4-chloro-3-buten-2-one 
• 18156-75-7 1-trimethylsilylpyrazole 

Relevant articles and documents

Organocatalytic Enantioselective Conjugate Alkynylation of β-Aminoenones: Access to Chiral β-Alkynyl-β-Amino Carbonyl Derivatives

Readily available potassium alkynyltrifluoroborates were used for organocatalytic asymmetric conjugate alkynylation of β-enaminones. The interception of a modified binaphthol catalyst and in situ generated organodifluoroboranes proved important to access functionalized β-alkynyl-β-amino carbonyls and derivatives with improved chemo-reactivity and enantio-induction. Mechanistic studies revealed the impact of molecular sieves on efficiency and stereocontrol. The products undergo additional functionalization to yield a diverse set of valuable β-alkynyl-β-amino carbonyl scaffolds.

Novel Bicycloannulation via Tandem Vinylation and Intramolecular Diels-Alder Reaction of Five-Membered Heterocycles: A New Approach to Construction of Psoralen and Azapsoralen

trans-4-(Phenylsulfinyl)-3-buten-2-one (1) was found to undergo a new versatile addition-elimination reaction with five-membered compounds such as furans, pyrroles, imidazole, pyrazole, and 6-(dimethylamino)fulvene to give an excellent yield of the corresponding trans-4-aryl-3-buten-2-ones (3).The thermal reaction of the propargyl ethers 7a,b prepared from 3a,b gave a single intramolecular Diels-Alder adduct, 8a,b, in 59percent and 38percent yields, respectively.Treatment of 7a,b with t-BuOK in refluxing tert-butyl alcohol afforded another type of Diels-Alder adduct, 10a,b, in almost quantitative yields.This bicycloannulation strategy was applied to a new synthesis of psoralen which is of current interest due to its unique photoreactivity with DNA.The acid-catalyzed reaction of sulfoxide 12, prepared from ethyl acatoacetate in high yield, with furan gave 13 in 78percent yield.The intramolecular Diels-Alder reaction of the neopentyl acetal of 13 in the presence of Pd/C followed by acid hydrolysis afforded the tricyclic ketone 18 in 38percent yield.Baeyer-Villiger oxidation and dehydrogenation of 18 completed the synthesis of psoralen (11).Furthermore, hitherto unknown azapsoralen 20 was also synthesized by this method.