Utility of the Enaminonitrile Moiety in the Synthesis of Some Biologically Active Thienopyrimidine Derivatives

Abstract

Because of its broad spectrum of biological activities, a novel series of thienopyrimidines and fused thienopyrimidines have been synthesized by reacting the enaminonitrile 1 with different reagents. Thus, reaction of 1 with urea, thiourea, formic acid and/or formamide afforded pyrimidine derivatives 2, 3, 4, and 5, respectively. Compound 4 reacted with POCl₃/PCl₅ giving the chloro-derivative 7 which upon treatment with thiourea, hydrazine, piperidine and/or thiols, produced 4-thio, 4-hydrazino, 4-piperidino- and 4-S-substituted pyrimidine derivatives 8–11, respectively. Treatment of 9 with ethyl chloroformate, sodium nitrite/hydrochloric acid, benzoyl chloride, acetic and/or formic acid, benzaldehyde/piperidine and CS₂/pyridine provided the carbazate 13, tetrazole 14, triazoles 15, and 16a, b, Schiff's base 17 and triazole 18, respectively. Some of the new synthesized compounds were screened for antibacterial activity. The structures of these compounds were confirmed by FT-IR, ¹H NMR and correct elemental analysis.

Keywords:

• Carbazate
• t-Butyltetrahydrobenzo[b]thiophene
• tetrazole
• thienopyrimidine
• triazole

Acknowledgments

The author is greatly appreciative to Prof. Dr. Fatma Farag, Biochemistry Department, Faculty of Science, Ain Shams University, for helping in doing the antibacterial activity for the newly synthesized compounds. Also, the author would like to express his deep appreciation to Prof. Dr. Hassan M.F. Madkour Prof. of Organic Chemistry, Chemistry Department, Faculty of Science, Ain Shams University for helping in revising this manuscript.

Notes

*MIC = minimum inhibitory concentration.