An expeditious synthetic approach towards the synthesis of Bis-Schiff bases (aldazines) using ultrasound

Abstract

Aldazines (Bis-Schiff bases) 1-24 were synthesized using aromatic aldehydes (heterocyclic and benzaldehydes) and hydrazine hydrate under reflux using conventional heating and/or via ultrasound irradiation using BiCl3 as catalyst. Ultrasonication conditions with cat. BiCl3 proved to be an effective, environmentally friendly synthetic procedure. This methodology is robust in the presence of electron donating and electron withdrawing groups affording desired products with high yields (>95%) in just a couple of minutes vs. hours using conventional heating.

Hydrolysis and Hydrazinolysis of Isatin-Based Ald- and Ketazines

“…These values do not match this reported for 2, 217-219 ∘ C. Our attempts to explore these unknown compounds guided us to assign structure 1,2-di(arylidene)hydrazines 6ad for the isolated compounds. We found that the analytical data of authentic samples of isolated compounds is identical with those of 6a-d [17][18][19][20]. Interestingly, refluxing 2 with aldehydes 3a-d in H 2 O/AcOH, 3,3 -(hydrazine-1,2diylidene)bis(indolin-2-one) (5) and aldazines 6a-d were also isolated.…”

Crystal structure of 1,1′-{(dodecane-1,12-diyl)bis[(azaniumylylidene)methanylylidene]}bis(naphthalen-2-olate)

“…Schiff base ligands can be easily synthesized using conventional or ultrasonic irradiation methods by reacting primary amines and carbonyl compounds in which the azomethine bond is formed and they can used to form complexes (Ouari et al, 2015a., Mohammadi et al, 2012Bhowmik et al, 2011., Grivani et al, 2013Nejo et al, 2009., Rayati et al, 2013., Khan et al, 2014., Kanagarajan et al, 2011.…”

“…For conventional synthesis of similar compounds, see: Ouari et al (2015a); Mohammadi & Rastegari (2012); Bhowmik et al (2011). For ultrasonic synthesis of similar compounds, see: Rayati & Abdolalian (2013); Khan et al (2014); Kanagarajan et al (2011). For related crystal structures, see: Ouari et al (2010Ouari et al ( , 2015b; Popović et al (2001); Friscic et al (1998); Bi et al (2012); Temel et al (2010).…”

Síntese Mecanoquímica De Azinas Acíclicas Simétricas E Determinação Do Fator De Proteção Solar Uvb in Vitro

“…21 Ademais, tem sido relatado o emprego de fontes alternativas de energia para obtenção de azinas acíclicas simétricas, como a de micro-ondas 12 e de ultrassom. 15 Outro método alternativo foi descrito no trabalho de Safari e Gandomi-Ravandi, no qual foi preparada uma série de azinas simétricas com altos rendimentos empregando energia mecânica gerada por moagem manual dos reagentes. 22…”