- Molecular design of pyrazolo[3,4-d]pyridazines
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Reactions of arenediazonium chlorides with ethyl 2-methyl-and 2-chloro-4-oxobutanoates gave, respectively, ethyl 2-(arylhydrazono)propanoates and chloro(arylhydrazono)acetates. Ethyl 2-(arylhydrazono)-propanoates reacted with the Vilsmeier-Haak reagent to give ethyl 1-aryl-4-formyl-1 H-pyrazole-3-carboxylates. Ethyl 1-aryl-4-acetyl-5-methyl-1H-pyrazole-3- carboxylates were obtained by reaction of chloro(arylhydrazono) acetates with acetylacetone. Reactions of the obtained pyrazole derivatives with hydrazine and methylhydrazine led to the formation of the corresponding 3,4-R 2 1 -6-R2-2-aryl-2,6-dihydro-7H-pyrazolo-[3,4-d]pyridazin-7- ones (R1, R2 = H, Me) which were subjected to alkylation and sulfurization.
- Matiichuk,Potopnyk,Obushak
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experimental part
p. 1352 - 1361
(2009/09/06)
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