68143-02-2

Upstream product

• 412339-20-9 4-methyl-6-oxo-1-phenyl-1,6-dihydropyridazine-3-carboxylic acid 
• 867-13-0 diethoxyphosphoryl-acetic acid ethyl ester 
• 5391-74-2 1-(phenylhydrazono)-propan-2-one 
• 4071-88-9 trimethylsilanyl-acetic acid ethyl ester 
• 83297-11-4 5-(1,2-diaza-3-methyl-1-phenylbutadien-4-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione 
• 100-34-5 benzene diazonium chloride 
• 67116-19-2 3-methyl-pentenedioic acid anhydride 
• 100-63-0 phenylhydrazine 
• 616-02-4 citraconic acid anhydride 
• 10071-49-5 4-methyl-1-phenyl-1,2-dihydro-pyridazine-3,6-dione 

Relevant academic research and scientific papers

A new and convenient synthesis of 3(2H)-pyridazinones by reacting carbanion of ethyl trimethylsilylacetate with phenylhydrazones

A one-pot synthesis of 5,6-disubstituted-2-phenyl-3(2H)-pyridazinones 4 is achieved on treatment of carbanion of ethyl trimethylsilylacetate with phenylhydrazones of 1,2-dicarbonyl compounds 1.

Reaction of triethyl phosphonoacetate anion with phenylhydrazones: A new method for the preparation of 3(2H)-pyridazinones

Various 5,6-disubstituted-2-phenyl-3(2H)-pyridazinones 4 have been synthesised by reacting triethyl phosphonoacetate anion with monophenylhydrazone of 1,2-dicarbonyl compounds 2.

The Reaction of Meldrum's Acid with α-Dicarbonyl Monohydrazones: A New Synthesis of Pyridazin-3-ones

Treatment of the monohydrazones of α-dicarbonyl compounds with Meldrum's acid gives the condensation products (13)-(19) under standard conditions.Reaction of pyruvaldehyde 2-phenylhydrazone or 2-t-butylhydrazone with Meldrum's acid at 80 deg C gives the corresponding 2-substituted-2,3-dihydro-6-methyl-3-oxo-pyridazine-4-carboxylic acids (29) and (30).Cyclisation of the other N-monosubstituted condensation products (13), (14), (16), (18), and (19) to 3-oxopyridazine-4-carboxylic acids (31)-(35) can be effected under basic conditions.Gas-phase pyrolysis of the N-aryl derivatives (13)-(16) at 550 deg C and 10E-2 Torr gives N-arylpyridazin-3-ones (38)-(41) while the N-t-butyl derivatives (18) and (19) at 750 deg C and 10E-2 Torr give N-unsubstituted pyridazin-3-ones (44) and (45) by additional loss of 2-methylpropene. 2-t-Butylpyridazin-3-ones (42) and (43) can be isolated from the same precursors under milder conditions (500 deg C and 10E-2 Torr).Pyrolysis of the N,N-dimethyl derivative (17) gave only polymeric material.