68337-35-9

Upstream product

• 19501-58-7 4-methoxyphenylhydrazine hydrochloride 
• 93-91-4 1-phenylbutan-1,3-dione 
• 1896-62-4 (E)-benzalacetone 
• 1381772-73-1 1-(4-methoxyphenyl)-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazole 
• 1428978-86-2 (Z)-1-(4-methoxyphenyl)-2-((E)-4-phenylbut-3-en-2-ylidene)hydrazine 
• 3471-32-7 4-Methoxyphenylhydrazine 
• 95514-24-2 (Z)-1-amino-1-phenyl-1-buten-3-one 
• 23652-90-6 (2Z)-3-amino-1-phenylbut-2-en-1-one 

Downstream Products

• 56426-41-6 3-methyl-5-phenylpyrazole 
• 106-51-4 p-benzoquinone 
• 1215212-21-7 C₁₇H₁₅FN₂O 

Relevant academic research and scientific papers

TBHP/Cu(OAc)2 mediated oxidation of pyrazolines: A convenient method for the preparation of pyrazoles

An efficient and simple oxidative protocol has been developed for the preparation of pyrazoles from pyrazolines mediated by TBHP/Cu(OAc)2 at room temperature. The present protocol has been successfully applied for the preparation of various pyrazole compounds from heterocyclic pyrazolines.

Copper-catalyzed aerobic C(sp2)-H functionalization for C-N bond formation: Synthesis of pyrazoles and indazoles

A simple, practical, and highly efficient synthesis of pyrazoles and indazoles via copper-catalyzed direct aerobic oxidative C(sp2)-H amination has been reported herein. This process tolerated a variety of functional groups under mild conditions. Further diversification of pyrazoles was also investigated, which provided its potential for drug discovery.

Microwave-mediated pyrazole fluorinations using selectfluor

Microwave-mediated electrophilic fluorinations and a new single-pot condensation en route to ring-fluorinated pyrazoles were examined: chemical equation represented The monofluorination by these methods was successful for a variety of pyrazoles, with yields ranging from 13% to 75%. While electrophilic aromatic fluorination of 3-CF3 pyrazoles proved largely ineffective, development ofa single-pot process overcame this limitation. The microwave-mediated reaction is regioselective; ring fluorination of the heterocycle occurs preferentially over phenyl and alkyl substituents. Alkyl side chain fluorination, when desired, can be modulated by reactant ratios. The single-pot method, which involves acid catalysis by H-TEDA, produces 4-fluoropyrazoles products.

A ceric ammonium nitrate N-dearylation of N-p-anisylazoles applied to pyrazole, triazole, tetrazole, and pentazole rings: Release of parent azoles. Generation of unstable pentazole, HN5/N5-, in solution

(Chemical Equation Presented) The reaction of cerium(IV) ammonium nitrate (CAN) with a range of N-(p-anisyl)azoles in acetonitrile or methanol solvents leads to N-dearylation releasing the parent NH-azole and p-benzoquinone in comparable yields. The scope and limitations of the reaction are explored. It was successful with 1-(p-anisyl)pyrazoles, 2-(p-anisyl)-1,2,3-triazoles, 2-(p-anisyl)-2H-tetrazoles, and 1-(p-anisyl)pentazole. The dearylation renders the p-anisyl group as a potentially useful N-protecting group in azole chemistry. The azole released in solution from 1-(p-anisyl)pentazole is unstable HN5, the long-sought parent pentazolic acid. p-Anisylpentazole samples were synthesized with combinations of one, two, and three 15N atoms at all positions of the pentazole ring. The unstable HN 5/N5- produced at -40°C did not build up in the solution but degraded to azide ion and nitrogen gas with a short lifetime. The 15N-labeling of the N3- ion obtained from all samples proved unequivocally that it came from the degradation of HN 5 (tautomeric forms) and/or its anion N5- in the solution.

Scope and limitations in the regioselective synthesis of 1,3,5-trisubstituted pyrazoles from β-amino enones and hydrazine derivatives. 13C-chemical shift prediction rules for 1,3,5-trisubstituted pyrazoles

β-amino enones react with hydrazine derivatives to give regioselectively 1,3,5-trisubstituted pyrazoles. The synthetic method only presents limitations when the β-substituent of the enone and the hydrazine substituent are bulky or possess an electron withdrawing character. Comparison of the 13C-NMR spectra of the seventy pyrazoles allowed us to estimate a 13C-chemical shift prediction rule for 1,3,5-trisubstituted pyrazoles, with deviations of less than ± 1 ppm.

Heterocyclic derivatives of 1-(1,3-dioxolan-2-ylmethyl)-1H-imidazoles

Heterocyclic derivatives of 1-(1,3-dioxolan-2-ylmethyl)-1H-imidazoles, useful as antifungal and antibacterial agents.