Synthesis of new pyrazole derived disazo dyes by ring closing reaction with the help of hydrazine derived compounds

In this thesis, 13 different substances, aniline and o-, m-, p- substituted aniline, were converted into diazonium salts by diazotizing with sodium nitrite and hydrochloric acid. Nitrile compounds (1a-1m) were synthesized by coupling diazonium salts with 3-aminocronanitrile. As a result of ring closing reaction of synthesized nitrile compounds (1a-1m) with 2-hydroxy ethyl hydrazine, amino pyrazole derivative 2a-2m substances were obtained. Pyrosole derivative (2a-2m) mono azo dyestuffs are re-formed into diazonium salts in the medium with sodium nitrite and pyridine. 3a-3m disazo dyestuffs were synthesized by coupling with the compound. After the synthesized 3a-3m disazo dyestuffs were purified, their structures and properties were explained by ATR-FTIR and 1H-NMR spectral data. In addition, the solutions of dyestuffs in different solvents were analyzed by UV-Vis spectrophotometer and the effects of solvent, substituent and acid-base were investigated by using the obtained findings.