Synthesis of Some Novel Class of Regioselective Spiro Isoxazolidine Derivatives via 1,3‐Dipolar Cycloaddition Reaction of N‐Benzyl‐C‐fluoro‐substituted Phenyl Nitrones in Ionic Liquid

Abstract

Synthesis of some new class of regioselective spiro isoxazolidine derivatives have been described using N‐benzyl‐C‐fluoro substituted‐phenyl nitrones with new dipolarophiles via 1,3‐dipolar cycloaddition reaction in ionic liquid. The novel spiro cycloadducts found to exhibit good synthetic potentiality as they could be converted into synthetically more important spiro 1,3‐amino alcohols. Simple reaction methodology, noninvolvent of catalysts, good to excellent yields, and greener approaches are the important features noticed in this syntheses.

Mechanochemical synthesis and cycloaddition reactions of fluoro nitrone under solvent‐free conditions and potential antimicrobial activities of the cycloadducts

“…Therefore, we can confirm that the isoxazoline derivatives underwent rearrangement to aziridine derivatives during mass fragmentation. On the basis of the spectral data of 1 H NMR, 13 C NMR, MS, and FT-IR, structures of all the synthesized isoxazolidine and isoxazoline derivatives (2-7) have been confirmed. We have also obtained satisfactory elemental analysis data for all the cycloadducts.…”

“…Bruker DRX 300 spectrometer (300 MHz, FT NMR) was used for recording 1 H NMR spectra and TMS was used as internal standard. Same instrument was used for recording 13 C NMR spectra at 75 MHz. The coupling constants (J) are expressed in Hz.…”

“…3.37 (s, 3H, ─COOCH 3 ), 3.28 (s, 3H, ─COOCH 3 ), 2.60 (s, 2H, C 6 H 5 CH 2 ), 1.74 (s,1H, C 3 H); 13…”

“…[9] It is also to be noted that because of low polarizability and high lipophilicity of the fluorine atom, it increases relative metabolic stability and improves the bioavailability of the new heterocyclic compounds compared with its hydrocarbon analogs. [10,11] In continuation of our efforts to establish various green methodologies in nitrone cycloaddition reactions, [12][13][14][15][16][17] herein, we wish to report the development of an environment-friendly mechanochemical route to isoxazolidine and isoxazoline derivatives using N-benzyl fluoro nitrone via 1,3-dipolar cycloaddition reactions (Scheme 1, Table 1).…”

“…Physicochemical data of synthesized molecules (2a-4a; All products were characterized by IR, 1 H NMR,13 C NMR, and MS spectral data.…”