10252-46-7

Upstream product

• 1128-54-7 3-methyl-1-phenyl-1H-pyrazole 
• 110706-26-8 1-(4-bromo-phenyl)-5-chloro-3-methyl-1H-pyrazole 
• 1016-41-7 5-ethoxy-3-methyl-1-phenyl-1H-pyrazole 
• 89975-71-3 1-Propyloxy-butanon-(3) 
• 59-88-1 phenylhydrazine hydrochloride 
• 78-94-4 methyl vinyl ketone 
• 100-63-0 phenylhydrazine 
• 6322-49-2 4-chloro-2-butanone 
• 590-90-9 1-Hydroxy-3-butanone 
• 60044-74-8 4-ethoxy-butan-2-one 
• 881-05-0 3-Methyl-1-phenyl-2-pyrazoline-4,5-dione 
• 105486-38-2 (1-Methyl-cyclopropyl)-phenyl-diazene 
• 107-80-2 1,3-dibromobutane 
• 588-64-7 benzaldehyde phenylhydrazone 

Downstream Products

• 1128-54-7 3-methyl-1-phenyl-1H-pyrazole 

Relevant academic research and scientific papers

Additive-free pd-catalyzed α-allylation of imine-containing heterocycles

An additive-free Pd-catalyzed α-allylation of different imino-group-ontaining heterocycles is reported. The activation of α-CH pronucleophiles (pKa (DMSO) > 25) occurs without the addition of strong bases or Lewis acids using only the Pd/Xantphos catalyst system. The reaction scope has been studied for various 5- and 6-membered nitrogen-containing heterocycles (yields up to 96%). Mechanistic investigations suggest an initial allylation of the imine-N followed by a Pd-catalyzed formal aza-Claisen rearrangement.

DABCO-catalyzed reactions of hydrazones with activated olefins

This paper describes several highly efficient DABCO-catalyzed aza-Michael addition reactions of hydrazones to activated olefins. In most cases, these aza-Michael addition reactions gave the corresponding products in high yields under mild conditions. The plausible reaction mechanism is discussed on the basis of deuterium labeling experiments. Upon treatment with HCl, the corresponding cyclized products can be obtained in high yields from the Michael addition products.

Unexpected ring opening of pyrazolines with activated alkynes: synthesis of 1H-pyrazole-4,5-dicarboxylates and chromenopyrazolecarboxylates

1H-Pyrazole-4,5-dicarboxylates and chromenopyrazole carboxylates were prepared by reacting pyrazolines with activated alkynes under neat conditions without a catalyst. The products were formed via unexpected ring opening of pyrazolines with the elimination of styrene/ethylene. These types of transformations are unknown and the products formed were confirmed using their spectral/analytical data. In addition, the structures of compounds 5e and 5n were confirmed by single-crystal X-ray analysis. Control experiments were conducted to support the proposed reaction mechanism.

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.

Zinc-catalyzed synthesis of pyrazolines and pyrazoles via hydrohydrazination

(Chemical Equation Presented) A novel regioselective synthesis of aryl-substituted pyrazolines and pyrazoles has been developed. Substituted phenylhydrazines react with 3-butynol in the presence of a catalytic amount of zinc triflate to give pyrazoline derivatives. The resulting products are easily oxidized in a one-pot procedure to the corresponding pyrazoles.

Aqueous N-heterocyclization of primary amines and hydrazines with dihalides: Microwave-assisted syntheses of N-azacycloalkanes, isoindole, pyrazole, pyrazolidine, and phthalazine derivatives

The synthesis of nitrogen-containing heterocycles from alkyl dihalides (ditosylates) and primary amines and hydrazines via a simple and efficient cyclocondensation in an alkaline aqueous medium that occurs under microwave irradiation is described. This improved greener synthetic methodology provides a simple and straightforward one-pot approach to the synthesis of a variety of heterocycles, such as substituted azetidines, pyrrolidines, piperidines, azepanes, N-substituted 2,3-dihydro-1H-isoindoles, 4,5-dihydropyrazoles, pyrazolidines, and 1,2-dihydrophthalazines.

Microwave-assisted cyclocondensation of hydrazine derivatives with alkyl dihalides or ditosylates in aqueous media: Syntheses of pyrazole, pyrazolidine and phthalazine derivatives

Direct syntheses of 4,5-dihydro-pyrazole, pyrazolidine, and 1,2-dihydro-phthalazine derivatives via double-alkylation of hydrazines by alkyl dihalides or ditosylates were accomplished in aqueous media under microwave irradiation conditions; the environmen

Oxidative Cyclization of β-Stannyl Hydrazones

Oxidation of β-stannyl hydrazones gave the corresponding azocyclopropanes in high yields.Homolytic cyclization involving hydrazonyl radicals (?-iminamino radicals) was postulated.