Synlett 2009(11): 1806-1808  
DOI: 10.1055/s-0029-1217186
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

[3+2] Cycloaddition of Oxaziridines with Nitriles: Synthesis of 2,3-Dihydro-1,2,4-Oxadiazoles

Luigino Troisi*, Ludovico Ronzini, Francesca Rosato, Valeria Videtta
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy
Fax: +39(0832)298732; e-Mail: luigino.troisi@unile.it;
Further Information

Publication History

Received 20 February 2009
Publication Date:
18 May 2009 (online)

Abstract

A new and simpler preparation of 2,3-dihydro-1,2,4 oxadiazoles by synchronous [3+2] cycloaddition between oxaziridines and nitriles is presented.

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Troisi, L.; Fabio, M.; Rosato, F.; Videtta, V. submitted.

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Reaction conducted according to general procedure.

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Reaction conducted using benzonitrile as solvent (10 mL) for 15 h according to the general procedure. Yields, after chromatographic purification, were about 80%.

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Compound 1: Crude product was purified by flash chromatography on silica gel deactivated with Et3N (PE-Et2O, 8:2). ¹H NMR (400 MHz, CDCl3): δ = 1.23 (s, 9 H), 6.11 (s, 1 H), 7.25-7.54 (m, 8 H), 7.98 (d, J = 8.1 Hz, 2 H). ¹³C NMR (100.62 MHz, CDCl3): δ = 25.0, 60.4, 85.8, 125.3, 126.6, 126.9, 128.0, 128.5, 131.9, 141.6, 161.4. GC-MS (70 eV): m/z = 280 (<1) [M+], 177 (50), 121 (35), 105 (20), 77 (25), 57 (100). FTIR (CHCl3): 3067, 2987, 2927, 2852, 1656, 1494, 1452, 1326 cm. Anal. Calcd for C18H20N2O: C, 77.11; H, 7.19; O, 5.71. Found: C, 77.09; H, 7.18; O, 5.69.

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Diastereomeric ratio determined by ¹H NMR on the crude product.