Synthesis of 3-phenyl-2H,5H-pyrano[3,2-c]chromen-2-one derivatives and their antineoplastic activity

Reaction of 4-oxo-4H-chromen-3-carbaldehydes 1 with phenylacetic acids 2 under mild conditions or microwave irradiation led to 3-phenyl-2-oxo-2H, 5H-pyrano[3,2-c]chromen-5-yl acetates 3. At stronger conditions by-products 5-(2-hydroxybenzoyl)-3-phenyl-2H-pyran-2-ones 4 and 5-hydroxy-2H, 10aH-pyrano[2,3-b]chromen-2-ones 5 were also obtained. 5-Hydroxy- and 5-alkyloxy-2H, 5H-pyrano[3,2-c] chromen-2-ones 6 and 7, respectively were easily prepared by reaction of 3 with water or alcohols. Twelve synthesized compounds were evaluated on their antineoplastic activities on 60 human tumour cell lines panels in NCI USA. According to the screening results 3-phenyl-2H, 5H-pyrano[3,2-c]chromen-2-one was discovered as a new leading skeleton suitable for further development. Some SAR conclusions were made. Antitubuline mechanism for the most active compound 3g has been proposed.