Reaction of Pyrrolobenzothiazines with Schiff Bases and Carbodiimides: Approach to Angular 6/5/5/5-Tetracyclic Spiroheterocycles

Abstract

1H-Pyrrole-2,3-diones, fused at [e]-side with a heterocycle, are suitable platforms for the synthesis of various angular polycyclic alkaloid-like spiroheterocycles. Recently discovered sulfur-containing [e]-fused 1H-pyrrole-2,3-diones (aroylpyrrolobenzothiazinetriones) tend to exhibit unusual reactivity. Based on these peculiar representatives of [e]-fused 1H-pyrrole-2,3-diones, we have developed an approach to an unprecedented 6/5/5/5-tetracyclic alkaloid-like spiroheterocyclic system of benzo[d]pyrrolo[3′,4′:2,3]pyrrolo[2,1-b]thiazole via their reaction with Schiff bases and carbodiimides. The experimental results have been supplemented with DFT computational studies. The synthesized alkaloid-like 6/5/5/5-tetracyclic compounds have been tested for their biotechnological potential as growth stimulants in the green algae Chlorella vulgaris.

Discovery of Novel and Selective Schiff Base Inhibitors as a Key for Drug Synthesis, Molecular Docking, and Pharmacological Evaluation

“…Acarbose, voglibose, and miglitol are α-glucosidase and α-amylase inhibitors that have received clinical approval. , However, these α-glucosidase and α-amylase inhibitors have been linked to side effects like diarrhea, gastrointestinal problems, and abdominal pain − and therefore development of novel antidiabetic drugs with increased efficacy and fewer side effects for the treatment of T2DM is required. In the area of medicinal chemistry, 1,2,4-thiadiazoles and Schiff base − are considered to be the most prominent subgroup of bioactive organic compounds with five-membered ring compounds and display a remarkable range of biological activities, including those for cyclooxygenase inhibition, human leukemia, antibacterial activity, , ulcerative activity, antihypertensive activity, cathepsin b inhibition, anticonvulsant activity, antidiabetic activity, and allosteric modulators …”