The synthesis of a series of new 4-imino-3,4-dihydro-1H-chromeno[2,3-d]pyrimidine-2(5H)-thiones 6(a-f) without substituent in C-5 position using microwave dielectric heating is reported. These new compounds were obtained in three steps with good overall yields (21-50%).

A four-step microwave-assisted reaction of N-3-susbstituted 4H-[1]-benzopyrano[2,3-d]pyrimidine-4(5H)-imines and formamidine derivatives was successfully developed from primary amines, cyclic secondary amines, and methyl N-(3-cyano-8-methoxy-4H-[1]-benzopyran-2-yl)methanimidate as key intermediate. The simplicity of the microwave protocols gave facile possibilities of isolation of the desired products by simple filtration. The synthesized compounds were obtained in good yields and purity, and characterized by 1H, 13C NMR, IR, and HRMS analyses.

No abstract

No abstract