Organobase-catalyzed one-pot three-component synthesis of novel pyrano[2,3- d ][1,3]thiazolo[3,2- a ]pyrimidine derivatives

An efficient, simple and fast procedure has been developed for the synthesis of a novel types of pyrano[2,3-d][1,3]thiazolo[3,2-a]pyrimidine derivatives through the one-pot three-component condensation reaction of 7-hydroxy-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-5-one, malononitrile and aromatic aldehydes in the presence DIPEA (N,N-diisopropylethylamine) as an available organo-base catalyst. This proposed procedure leads to the synthesis of desired products in short reaction times (5–10 min) and excellent isolated yields (90–94%).