Synthesis, in vitro Α-Glucosidase, and acetylcholinesterase inhibitory activities of novel Indol-Fused Pyrano[2,3-D]Pyrimidine compounds

•New indol-fused pyrano-[2,3-d]pyrimidines 11a-l were designed and synthesized.•The plausible mechanism for formation of compounds 11a-l was described.•Their α-glucosidase and acetylcholinesterase inhibitory activities were evaluated.•α-Glucosidase inhibitors 11d,e were around 93-fold more potent than acarbose.•Product 11 k exhibited good acetylcholinesterase inhibitory activity.