Synthesis of Analogues of Indole Alkaloids from Sea Sponges - Aplysinopsins by the Reaction of Amines with (4Z)-4-[(1H-indol-3-yl)-methylene]-1,3-oxazol-5(4H)-ones

A new two-step approach toward the synthesis of aplysinopsin analogues 5-(1-R-1H-indol-3-ylmethylene)-2-aryl-3,5-dihydroimidazol-4-ones consisting in obtaining and reaction of 4-(1-R-1H-indol-3-ylmethilene)-2-Ar-4H-oxazol-5-ones with amines was developed. The configuration of starting compounds and final products was determined by 13С and 1H-nmr spectroscopy.