Synthesis and glycosidase inhibitory activity of novel (2-phenyl-4H-benzopyrimedo[2,1-b]-thiazol-4-yliden)acetonitrile derivatives

Novel (2-phenyl-4H-benzopyrimido[2,1-b][1,3]thiazol-4-yliden)acetonitrile derivatives (4a–m) have been synthesized and tested for antidiabetic activity. A series of (2-phenyl-4H-benzopyrimodo[2,1-b][1,3]thiazol-4-yliden-4-yliden)acetonitrile derivatives have been prepared by ring transformation reaction of 4-(methylthio)-2-oxo-6-aryl-2H-pyrane-3-carbonitriles. The yield of ring transformation product is moderate to good. Furthermore the glycosidase inhibitory activities were tested by using α-amylase and α-glucosidase pancreatic, intestinal and liver enzymes, responsible for hyperglycemia in type II diabetes. The results revealed that all compounds exhibit significant glycosidase inhibitory activity.