Synlett 2002(6): 0947-0951
DOI: 10.1055/s-2002-31901
LETTER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of 3,4-Diarylsubstituted Maleic Anhydride/Maleimide via Unusual Oxidative Cyclization of Phenacyl Ester/Amide [1]

Vijaya Raghavan Pattabiraman, Srinivas Padakanti, Venugopal Rao Veeramaneni, Manojit Pal*, Koteswar Rao Yeleswarapu
Discovery Chemistry, Dr. Reddy’s Research Foundation, Bollaram Road, Miyapur, Hyderabad 500050, India
Fax: +91(40)3045438/3045007; e-Mail: manojitpal@drreddys.com;
Weitere Informationen

Publikationsverlauf

Received 28 March 2002
Publikationsdatum:
07. Februar 2007 (online)

Preview

Abstract

A simple and general method has been developed for the synthesis of 3,4-diarylsubstituted maleic anhydride and maleimide through tandem cyclization and oxidation reaction of phenacyl ester or amide. A wide variety of phenacyl esters or amides was treated with DBU under oxygen atmosphere to give the expected compounds in good to excellent yield. Mechanism of the reaction and application of the methodology have been discussed.

1

DRF Publication No. 185.

1

DRF Publication No. 185.

21

A useful method for the synthesis of 3,4-diaryl-5-hydroxyfuranones has been developed by us and will be reported elsewhere.

23

Typical Procedure for the Synthesis of 3,4-Diaryl Substituted Maleic Anhydride: Preparation of 4: To a solution of 2-oxo-2-phenylethyl-2-phenylacetate (0.50 g, 1.968 mmol) in acetonitrile (8 mL) was added DBU (0.899 g, 5.905 mmol) slowly and dropwise at 25 °C in the presence of atmospheric oxygen. The mixture was stirred for 6 h. After completion of the reaction the mixture was poured into ice-cold 3 N HCl solution (20 mL) with stirring. The solid separated was filtered off, washed with water (2 × 10 mL) followed by petroleum ether (2 × 5 mL). Compound 4 was isolated in 77% yield as light yellow solid, mp 158-160 °C (lit [16] 159-160 °C).

24

Spectral data for 11: mp: 161.5-162 °C (1:9 EtOAc-hexane); IR max (KBr): 1833, 1766 cm-1; 1H NMR (200 MHz, CDCl3): δ = 7.31-7.54 (m, 5 H), 7.74 (d, J = 8.74 Hz, 2 H), 8.27 (d, J = 8.79 Hz, 2 H); Mass (CI method, I-butane): m/z (%) = 296(100) [MH+]; UV (MeOH): 268 nm. Elemental analysis found: C, 64.81; H, 3.11; N, 4.62. C16H9NO5 requires C, 65.09; H, 3.07; N, 4.74.

25

Spectral data for 12: mp: 121-122 °C (1:9 EtOAc-hexane); IR max (KBr): 1826, 1757 cm-1; 1H NMR (200 MHz, CDCl3): δ = 2.38 (s, 3 H), 7.18-7.26 (m, 3 H), 7.39-7.56 (m, 6 H); Mass (CI method, I-butane): m/z (%) = 265(100) [MH+]; UV (MeOH): 355 nm. Elemental analysis found: C, 77.55; H, 4.32. C17H12O3 requires C, 77.26; H, 4.58.