Synthesis of tetrahydrofuro[3,2-c]pyridines via Pictet–Spengler reaction

Abstract

A semi-one-pot method for the synthesis of 4-substituted tetrahydrofuro[3,2-c]pyridines by the Pictet–Spengler reaction was developed. The method is based on the condensation of easily accessibly 2-(5-methylfuran-2-yl)ethanamine with commercially available aromatic aldehydes followed by acid-catalyzed Pictet–Spengler cyclization. Using this approach, we synthesized a range of 4-substituted tetrahydrofuro[3,2-c]pyridines in reasonable yields. The reactivity of some of the products was investigated and selected synthetic transformations of the obtained tetrahydrofuro[3,2-c]pyridines were shown.

Keywords

• acid hydrolysis
• 1,4-diketone
• tetrahydrofuro[3,2-c]pyridines
• paal–knorr reaction
• pictet–spengler reaction