Synthesis and In Vitro Antitumor Activity of New Isoxazolo[5,4‐d]Pyrimidine Systems

Abstract

The reaction of 5‐amino‐3‐methylisoxazole (1) with aldimines 2, 3, 4, 5, 6, 7 gave basic side chain 5‐amino‐3‐methylisoxazole derivatives 8, 9, 10, 11, 12, 13. Annulations of derivatives 8, 9, 10, 11, 12, 13 with anisaldehyde afforded the target isoxazolo[5,4‐d]pyrimidines 14, 15, 16, 17. Treatment of 1 with isatin ketimine anil 18 resulted in the formation of derivative 19, which further cyclized with anisaldehyde afforded the spirotetracyclic system 20. Mannich reaction of 1 with primary amine such as methylamine and benzylamine gave the corresponding isoxazolo[5,4‐d]pyrimidine derivatives 21 and 22, respectively. The newly synthesized compounds were tested for their antitumor activity.

Highlights on the synthesis of novel phenothiazine‐based azines scaffold as antioxidant agents

“…In addition, drug containing pyrimidine nuclei are reported to have variable biological and therapeutic activities . Condensed pyrimidines are known as highly potent antimicrobial , analgesic, antiviral, anti‐inflammatory, and antitumors …”