A flexible approach to the chromenoquinolines under copper/lewis acid catalysis

S Ramesh, V Gaddam, R Nagarajan

Index: Ramesh, Subburethinam; Gaddam, Vikram; Nagarajan, Rajagopal Synlett, 2010 , # 5 p. 757 - 760

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Citation Number: 17

Abstract

Herein, we report the synthesis of 6H-chromeno[4,3-b]quinolines using the mixture of copper(I) iodide and lanthanum triflate as an efficient catalysts. Initially, we examined the reaction between aniline (1a) and O-propargylated salicylaldehyde 2a as starting materials using different catalysts to optimize the reaction conditions (Scheme [¹] ). It was found that 10 mol% of BF 3 ˙OEt 2 as a Lewis acid was not much useful to obtain the desired product and only 20% ...