Pyridazines attract much attention due to their biological activity [1], some of them are used in the treatment of Parkinson, Alzheimer, and other neurodegenerative diseases [2,3]. 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 aim of our study was the elucidation of the possibility to obtain 3,4,5,6-tetrasubstituted pyridazines by the intermolecular diaza-Wittig reaction of phosphazines of acyclic diazoketoesters with 1,3-diketones and ketoesters .We used as diazo substrates methyl and ethyl 2-diazo-3-oxo-4,4,4-trifl uorobutanoates (Iа, Ib), аnd as 1,3-dicarbonyl compounds ketoesters IIa, IIb and diketones IIc, IId. In the preparation of the phosphazines from diazoketoesters I we applied the triphenylphosphine (IIIа) commonly used in the Staudinger reaction [11][12][13] and more nucleophilic [14] tris(dimethylamino)phosphine (IIIb).The reaction of diazoketoesters Iа, Ib with ketoester IIа was carried out similarly to procedure [10] using PPh 3 . It presumably proceeded with the intermediate formation of triphenylphosphazines IVа, IVb and was of low effi ciency. The monitoring of the reaction progress by 1 Н NMR spectroscopy showed that under these conditions a fairly complex mixture of products formed containing alongside the target compounds also a diazoacetic ester phosphazine and the other reaction products, and according to the data of 1 Н NMR spectrum of the reaction mixture the yield of pyridazines V did not exceed 30-32%.

diaza-Wittig Reactions of Diketoesters Phosphazines: Synthesis of Tetrasubstituted Fluoroalkyl-Containing Pyridazines. -(SUPURGIBEKOV, M. B.; YANYUK, N. S.; NIKOLAEV*, V. A.; Russ. J. Org. Chem. 47 (2011) 8, 1252-1255, http://dx.doi.org/10.1134/s1070428011080240 ; St. Petersburg State Univ., St. Petersburg 198504, Russia; Eng.) -R. Langenstrassen 07-155