An Approach towards the synthesis of furo[3,4-c]pyrazole

Abstract

Synthesis of pyrazole and its N-aryl analogues has been a subject of consistent interest because of the wide applications of such heterocycles in pharmaceutical as well as in agrochemical industry. Numerous compounds containing pyrazole moiety have been shown to exhibit antihyperglycemic, analgesic, anti-inflammatory, antipyretic, antibacterial, and sedative-hypnotic activity. The 1-phenylpyrazole motif is present in several drug candidates for treatment of various diseases such as cyclooxygenase-2 (Cox-2) inhibitors, IL-1 synthesis inhibitors, and protein kinase inhibitors etc. Similarly a few of the 1, 5-diarylpyrazole derivatives have been shown to exhibit nonnucleoside HIV-1 reverse transcriptase inhibitory activities along with Cox-2 inhibitor. Pyrazoles are usually prepared by condensation between a hydrazine derivative and a 1,3-dicarbonyl compound or by 1,3-dipolar cycloaddition of diazoalkanes or nitrile imines to olefins or acetylenes. Here, in this report our approach towards the synthesis of some polycyclic pyrazole compounds by the Diels-Alder reaction of furo[3,4-c]pyrazole and several dienophiles is disclosed. As furo[3,4-c]pyrazole is unknown till now, we want to focus our study for the synthesis of furo[3,4-c]pyrazole