Francesco De Sio

The reactivity of 3-methyl-4-nitro-5-styrylisoxazole with some bis-enolisable ketones

The expected Michael adducts and spiroisoxazolines are obtained from the reaction between 3-methyl-4-nitro-5-styrylisoxazole and bis-enolisable ketones. Contrary to reported data, Michael adducts are obtained in good yields only when a substoichiometric amount of base is used, whereas spiroisoxazolines were obtained as the major product when the base is present in a large excess.

Permanganate oxidation of 3-methyl-4-nitro-5-styrilisoxazole: a correction

Abstract In contrast with a previous report, permanganate oxidation of the title compound 3 gives the nitroisoxazolone 8 and not 3-methyl-4- nitroisoxazole-5-carboxylic acid 2 ; a reaction pathway, involving the spirocyclisation of the carboxylate 10 , is suggested.

Solid State Photodimerization Reaction of Some 3-Sytrylisoxazolo[3,4-d]pyridazin-7(6H)-ones

Photodimerisation des composes du titre en diphenyl-1,3- (ou bis-[chloro-4 phenyl]-1,3) bis-[dihydro-6,7 dimethyl-4,6 oxo-7 isoxazolo [3,4-d] pyridazinyl-3]-24 cyclobutanes (identifies par donnees spectrales et oxydation en les acides diaryl-2,4 cyclobutanedicarboxyliques-1,3)

Polyazaheterocyclic compounds: condensation reactions of pyridazine-4,5-dicarboxylic acid derivatives with o-phenylenediamine

Diethyl pyridazine-4,5-dicarboxylate (II) and its 3,6-dimethyl derivative (XIV) cyclised with o-phenylenediamine in the presence of sodium hydride to give 6,11-dihydropyridazino[4,5-c][1,6]benzodiazocine-5,12-dione (III) and its 1,4-dimethyl derivative (XV), respectively. By heating under reduced pressure these compounds were dehydrated to the corresponding pyridazino[4′,5′:3,4]pyrrolo[1,2-a]benzimidazol-11-ones (XII) and (XX).Compound (III) reacted with diazomethane yielding a mixture of di-N-methyl (IV), NO-dimethyl (V), and di-O-methyl (VI) derivatives. Mild alkaline hydrolysis of the dione (III) afforded 5-(o-aminophenylcarbamoyl)-pyridazine-4-carboxylic acid (VII), which cyclised to 5-(benzimidazol-2-yl)pyridazine-4-carboxylic acid (VIII). Heating compound (III) with hexamethylphosphoric triamide gave NN-dimethyl-5-(benzimidazol-2-yl)pyridazine-4-carboxamide (XI).3,6-Dimethylpyridazine-4,5-dicarboxylic anhydride (XVI) reacted with o-phenylenediamine at room temperature to give 3,6-dimethyl-5-(o-aminophenylcarbamoyl)pyridazine-4-carboxylic acid (XVII), whereas when refluxed with the same reagent in acetic acid it afforded 2-(3,6-dimethylpyridazin-4-yl)benzimidazole (XVIII).