Synthesis of tetrahydrobenzobpyran derivatives catalysed by Aliquat~?336 in water under microwave irradiation

摘要

A series of 4H-5,6,7,8-tetrahydrobenzobpyran derivatives has been synthesised in excellent yield in a single pot using trioctylmethylammonium chloride (Aliquat~?336) as phase-transfer catalyst in water under microwave irradiation. This method provides a clean access to the desired products. The structures of the products were confirmed by IR,~1H NMR,~(13)C NMR in all cases and HRMS in several cases, and supported by single crystal X-ray diffraction analysis of 2-amino-4-(3-benzyloxy-4-methoxyphenyl)-3-cyano-7,7-dimethyl-5-oxo-4H-5,6,7,8-tetrahydrobenzobpyran and 2-amino-3-cyano-4-(3-iodo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-5-oxo-4H-5,6,7,8-tetrahydrobenzob pyran.