Chromene phosphonic acid diethyl ester

Keywords Chromene phosphonic acid diethyl ester, salicylaldehydes, malononitrile, triethyl phosphate, ethanol, room temperature, one-pot multicomponent synthesis... 

Jayashree, P., Shanthi, G., and Pemmal, P. T. (2009). Indium trichloride catalyzed one-pot synthesis of new (2-amino-3-cyano-4//-chromen-4-yl) phosphonic acid diethyl ester. Synlett, 917-920. 

Keywords Salicylaldehydes, malononitrile/ethyl cyanoacetate, triethylphosphite, nanocrystalline MgO heterogeneous catalyst, ethanol-water (1 1), room temperature, one-pot three-component synthesis, (2-amino-3-cyano-4//-chromen-4-yl)phosphonic acid diethyl esters... 

In 2011, Pore and his group reported a room temperature method for the rapid and efficient synthesis of (2-amino-3-cyano-4//-chromen-4-yl) phosphonic acid diethyl esters (34) via a single-step multi-component reaction of structurally diverse salicylaldehydes (32) with malononitrile (33) and triethyl phosphite, using a catalytic amount of potassium phosphate, in ethanol (Scheme 14). Use of potassium phosphate as an inexpensive catalyst, mild reaction conditions, and a simple work-up procedure are the added advantages of the present method. 

In the following year (2012), Rao Kolia and Lee extended the reaction for the synthesis of such biologically relevant 2-amino-4//-chromen-4-ylphosphonate derivatives (35) from the one-pot three-component condensation of substituted salicylaldehydes, malononitrile (or ethylcyanoacetate) and triethylphosphite in the presence of ethyle-nediamine diacetate (EDDA) as a catalyst in alcohol under room temperature conditions (Scheme 15). Recently, Brahmachari and Laskar (2014) have also developed an energy-efficient multicomponent one-pot procedure for the facile synthesis of a wide range of diverse (2-amino-3-cyano-4/f-chromen-4-yl)phosphonic acid diethyl esters at room temperature from the reaction of salicylaldehydes, malononitrile (or ethyl cyanoacetate) and triethylphosphite on the surface of a reusable heterogeneous MgO-nanocatalyst in aqueous ethanolic... 

Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl ester 35... 

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