An efficient and green method for the synthesis of [1,3]oxazine derivatives catalyzed by thiamine hydrochloride (VB1) in water
作者:Valmik D. Dhakane、Somnath S. Gholap、Umesh P. Deshmukh、Hemant V. Chavan、Babasaheb P. Bandgar
DOI:10.1016/j.crci.2013.06.002
日期:2014.5
Résumé An efficient and convenient synthesis of 1,3-oxazine derivatives has been achieved by the one-pot, multicomponent condensation of α- or β-naphthol, an aniline and formaldehyde using thiamine hydrochloride (VB1) as a versatile biodegradable and reusable catalyst in water as a universal solvent.
Oxazine derivatives can be prepared with yield upto 98% within a few minutes by an efficient and novel one pot microwave- assisted three- componentreaction from 1-naphthol, various anilines and formalin using montmorillonite as the catalyst. The procedure is very simple, efficient and environmentally friendly as it does not use any toxic auxiliary or solvent. The key advantages of this process are