Synthesis of some new 5H-piridazino[4,5-b]indole derivatives

Author: Vasil Badalashvili
Keywords: pyridazino[4, 5-b]indole, indole, synthesis, organic chemystry
Annotation:

carried out the diazotization of 2-bromo-4-methylalanine, the azo conjugation of this product with ethyl 2-methylacetoacetate and the hydrolyze in one step without extraction of azoester by japp-klingeman. The indolization of ethyl 2-(2-(2-Bromo-4-methylphenyl)hydrazineylidene)propanoate was carried out by Fisher indolization in polyphosphoric acid. 7-bromo-3-formyl-2-ethoxycarbonyl-5-methylindole was obtained by formylation of 7-bromo-2-ethoxycarbonyl-5-methylindole. The reflux of 7-bromo-3-formyl-2-ethoxycarbonyl-5-methylindole with hydrazine hydrate in acetic acid allows the formation of a target product 6-bromo-5-methyl-4-oxo-3H,5H-piridazino[4,5-b]indole. In order to synthesize chloride containing compounds, 6-bromo-4-chloro-5methyl-5H-piridazino-[4,5-b]indole, the target product was refluxed with POCl3. The presence of halogen atoms in these compounds makes the possibility of the substitution this group by the amino -, hydrazine -, ciano - and other groups.