1157-37-5

Upstream product

• 77435-32-6 4-(N'-4-methoxybenzoyl-N'-phenylhydrazino)pent-3-en-2-one 
• 100-63-0 phenylhydrazine 
• 108086-92-6 3-benzoyl-4-(methylamino)-3-penten-2-one 
• 51294-75-8 4-bromo-3,5-dimethyl-1-phenyl-1H-pyrazole 
• 98-88-4 benzoyl chloride 
• 387353-96-0 3,5-dimethyl-4-dimethylphenylsilyl-1-phenylpyrazole 
• 123-54-6 acetylacetone 
• 1131-16-4 3,5-dimethyl-1-phenyl-1H-pyrazole 
• 55685-56-8 N-4-methoxybenzoyl-N-phenylhydrazine 
• 343866-81-9 3-benzoyl-4-(t-butylamino)-3-penten-2-one 
• 59487-13-7 N-tert-butyl-4-amino-3-penten-2-one 

Relevant academic research and scientific papers

Reactions of 3,5-dimethyl-1-phenyl-1h-pyrazole with electrophiles

Reactions of 3,5-dimethyl-1-phenyl-1H-pyrazole with various electrophilic reagents were studied. Electrophilic attack occurred regioselectively at the C4 atom in the pyrazole ring. Pleiades Publishing, Ltd., 2012.

Study of the reactivity of α-acylenaminoketones. Synthesis of pyrazoles

The reactions of 4-(methylamino)-3-penten-2-one with diazoketones yielded the α-acylenaminoketones 1-3 in good yields. Preparation of the α-acylenaminoketone 4 was carried out by treatment of 4-(t-butylamino)-3-penten-2-one with benzoyl chloride being followed by reaction of transamination with methylamine. The reactions were carried out in five different solvents and were submitted to gas chromatography/mass spectrometry analysis, with the goal of obtaining substituted pyrazoles and determining which of the carbonyls would preferentially be attacked by the nucleophile. The reactions of compounds 1-4 with hydrazine reagents led to the formation of the pyrazoles 5-7a-q. Small amounts of 4-methylamino-2-pentenones 10a-q, amides 11a-q and pyrazoles 12a-q were also obtained in these reactions. The unexpected formation of pyrazoles 15d,h,q was detected when methanol and N,N-dimethylformamide were used as solvents in the reactions of α-acylenaminoketone 4 with hydrazine reagents.

Synthesis and reactions of silylated and stannylated 1,2-azoles

Silicon or tin 4-metalated pyrazoles and isoxazoles are synthesized by silyl- or stannylcupration from 4-haloazoles. On the other hand, 5-metalated pyrazoles are prepared by reaction of 5-un-substituted pyrazoles with LDA and subsequent treatment with chlorosilanes and chlorostannanes. Furthermore, starting from 5-unsubstituted 4-halopyrazoles and applying both methodologies, 4,5-dimetalated pyrazoles bearing silyl groups different from trimethylsilyl or tributylstannyl groups are obtained. Some regioselective ipso-substitutions are also studied.

Synthesis of 4-Acyl- and 4-Alkoxy-carbonylpyrazoles

N'-Aroyl- or N'-acetyl, N'-phenyl- or N'-methyl-hydrazino-derivatives (1) of 1,3-dicarbonyl compounds can be converted by mild base treatment into 5-aryl- or 5-methyl-, 1-phenyl- or 1-methylpyrazoles carrying an acyl or alkoxycarbonyl group at C-4.