Diammonium Hydrogen Phosphate: An Efficient and Versatile Catalyst for the One‐Pot Synthesis of Tetrahydrobenzo[<i>b</i>]pyran Derivatives in Aqueous Media
Diammonium hydrogen phosphate was used as a mild, efficient, neutral, and cheap catalyst for the synthesis of various 4H-benzo[b]pyran derivatives via a one-pot, three-component condensation of aromatic aldehydes, active methylene compounds, and dimedone in aqueous media.
An eco-friendly approach for synthesis of novel substituted 4H-chromenes in aqueous ethanol under ultra-sonication with 94% atom economy
作者:Surya Narayana Maddila、Suresh Maddila、Mandlenkosi Khumalo、Sandeep V.H.S. Bhaskaruni、Sreekantha B. Jonnalagadda
DOI:10.1016/j.molstruc.2019.03.006
日期:2019.6
Abstract An operational approach for synthesis of eleven substituted 4H-chromene derivatives by one-pot, three-component reaction of aromatic aldehyde, methyl cyanoacetate and cyclic diketone through ultrasound irradiation, in the presence of aqueous ethanol under catalyst-free condition is reported. Different spectral methods, including 1H, 13C and 15N NMR and HRMS were utilized to characterize the