A mild and efficient method for the synthesis of a new class of furo[3,2-c]chromenes in aqueous media.
An efficient synthesis of 2-hydroxy-3-[2-oxo-2-phenylethylidene]-2-phenyl-2, 3-dihydro-4 H-furo[3, 2-c]chromene-4(2H)-one is described. This involves the reaction between dibenzoylacetylene and 4-hydroxycoumarine in the presence of NaH (10 mol %) in nearly quantitative yield. Treatment of this heterocyclic system with trimethyl chlorosilane in CHCl(3) leads quantitatively to 4-oxo-3-[2-oxo-2-phenylethylidene]-2-phenyl-3H, 4H-furo[3,2-c]chromene-1-ium chloride. Direct addition of nucleophiles, such as alcohols, amines or trialkyl phosphites to this salt in water as the solvent produces functionalized 2-phenyl-4H-furo[3,2-c] chromen derivatives in excellent yields.
Khalilzadeh
Mohammad A
MA
Chemistry Department, Islamic Azad University, Qaemshahr Branch, P.O. Box 163, Mazandaran, Iran. m.khalilzadeh@hotmail.com
Hossaini
Zinatossadat
Z
Charati
Faramarz Rostami
FR
Hallajian
Sara
S
Rajabi
Mehdi
M
D000438:Alcohols / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry; D002621:Chemistry / Q000379:methods*
D000438:Alcohols; D000588:Amines; D001578:Benzopyrans