177494-48-3Relevant academic research and scientific papers
SYNTHESIS OF NITROGENOUS COMPOUNDS. Part -V
Mokhtar, H. M.,Farahat, O. O.
, p. 33 - 43 (2007/10/03)
Condensation of 3,4-disubstituted-but-3-en-2-ones (3) with hydrazines produced the hydrazones (4) which with ethanolic HCl underwent cyclization to the pyrazolines (5).Oxidation of (5) with bromine-water furnished the pyrazoles (6).Similarly, condensation of (3) with acylhydrazines generated the acylhydrazones (7).Ethyl 6-aryl-2,4-dioxo-5-substituted hexenoates (8) has been synthesized by condensation of 3,4-disubstituted-but-3-en-2-ones (3) with ethyl oxalate.Esters (8) on reaction with hydroxylamine afforded the isoxazole esters (9), whereas, with acylhydrazines furnished the acylhydrazones (10) which were cyclized to N-acylpyrazoles (11).With hydrazines, compounds (8) underwent cyclization to the pyrazole esters (12) which were converted either to the acids (13; R2=OH) or to the acid hydrazides (13; R2=NHNH2).Reaction of (12; R'=C6H4SO2NH2(p)) with the appropriate isothiocyanate derivatives produced benzenesulphonylthioureas which with ethyl bromoacetate and ethyl β-bromopropionate furnished 2-iminothiazolidinones (15) and 2-iminothiazinones (16) respectively.Moreover, esters (8) with o-phenylenediamine yielded the oxyquinoxalines (17). - Key words: Synthesis, Heterocyclic compounds.
