Synthesis of 4-fluoroalkyl-substituted pyridazines from fluorinated diazodiketones

diaza-Wittig reactions of diketoesters phosphazines: Synthesis of tetrasubstituted fluoroalkyl-containing pyridazines

“…Therefore the development of new methods of preparation of this class compounds is an urgent problem of the synthetic organic chemistry.In keeping with published reports 3,4,6-trisubstituted pyridazines can be synthesized in good yields from 2-vinyl derivatives of 2-diazoketones by the intramolecular diaza-Wittig reaction [4][5][6][7][8][9]. The only example of the synthesis of the tetrasubstituted pyridazine with the use of analogous procedure was described in [10], where by the diaza-Wittig reaction of the posphazine of 4-diazopyrrolidinetrione with ethyl acetoacetate bicyclic pyrrolo[3,4-c]pyridazine was obtained.…”

“…The signals of atoms С 3 at 152.8, 153.1 and of С 6 at 148.7 and 148.6 q ( 2 J C-F 35.9 Hz) in the spectra of pyridazines Vа, Vb, and also 152.8, 153.1 (C 3 ), 148.1 q (C 6 , 2 J C-F 35.9 Hz) in the spectra of VIа, VIb are located in the region of the 13 С NMR spectra characteristic of unsubstituted [15] and trisubstituted pyridazines [5,7,9].…”

Synthesis of 4-trifluoromethyl pyridazines via annulation of pyridinium ylides with trifluoroacetyl diazoester

“…18 In general usage, the condensation of hydrazine with a γ-(trifluoromethyl)diketone was the most common method to introduce the trifluoromethyl substituent into a pyridazine (Scheme 1a). [19][20][21][22] Trifluoromethylated pyridazine derivatives have also been synthesized through the Staudinger/intramolecular diaza-Wittig sequence starting from trifluoromethyl-containing diazodiketones (Scheme 1b) 23,24 or the [2 + 1]/[3 + 2]-cycloaddition sequence using (trifluoromethyl)diazomethane and alkynes (Scheme 1c). 25 We also recently reported a method for the synthesis of pertrifluoromethyl pyridazine derivatives via a tandem reaction of aryldiazonium salts with hexafluoroacetylacetone.…”

Microwave‐enhanced Efficient Synthesis of Some Polyfunctional Pyridazines

“…Pyridazines and its myriad derivatives continue to attract significant attention in pharmaceutical industry in the quest to search new drugs because of its wide spectrum applications as pharmacologically important compounds, viz. antimicrobial , analgesic , anticancer , antitubercular , cyclooxygenase (COX) inhibitor , antidiabetic , antiviral , and so on.…”