Synlett 2004(5): 0886-0888  
DOI: 10.1055/s-2004-820018
LETTER
© Georg Thieme Verlag Stuttgart · New York

A New Synthetic Method of 1,4-Dihydro-2H-3,1-benzoxazin-2-ones: Selenium-Catalyzed Reductive Carbonylation of Aromatic Nitro Compounds with Carbon Monoxide

Yutaka Nishiyama*, Yoshitaka Naitoh, Noboru Sonoda*
Department of Applied Chemistry, Faculty of Engineering, Kansai University, Suita, Osaka 564-8680, Japan
e-Mail: nishiya@ipcku.kansai-u.ac.jp;
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Publikationsverlauf

Received 25 December 2003
Publikationsdatum:
24. Februar 2004 (online)

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Abstract

It was confirmed that selenium catalyzed the reaction of 2-nitrobenzyl alcohols with carbon monoxide to afford 1,4-dihydro-2H-3,1-benzoxazin-2-ones in good yields. Similarly, seven-membered cyclic carbamate was prepared by the reaction of 2-(2-nitrophenyl)ethanol with carbon monoxide.

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When 1a was treated with carbon monoxide and water (5 equiv) in the presence of a catalytic amount of selenium at 150 °C for 5 h, 2a was not obtained and 2-aminobenzyl alcohol was formed in 87% yield.

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A Typical Procedure is as follows: In a 50 mL stainless steel autoclave were placed o-nitrobenzyl alcohol (77 mg, 0.5 mmol), selenium (8 mg, 0.1 mmol), N-methylpyrrodine (425mg, 5 mmol), THF (5 mL) and a magnetic stirring bar. The mixture was stirred under pressurized carbon monoxide (30 atm) at 140 °C for 5 h. After the evacuation of the excess carbon monoxide at r.t., the deposited selenium was filtered off; the solution was then extracted with diisopropyl ether (30 mL × 3). The organic layer was dried over MgSO4 and the solvent was evaporated in vacuo. The residual solid was recrystallized from CH2Cl2-C6H14 to give 1,4-dihydro-2H-1,3-benzoxazine-2-one in 85% yield.
Compound 2g: 1H NMR (d 6-DMSO): δ = 2.50 (s, 1 H), 3.34 (br s, 1 H), 5.17 (t, J = 5.2 Hz, 1 H), 5.35 (t, J = 4.0 Hz, 1 H), 6.83 (t, J = 8.0 Hz, 1 H), 6.98 (t, J = 8.0 Hz, 1 H), 7.21 (q, J = 8.0 Hz, 2 H), 10.41 (s, 1 H). 13C NMR: δ = 63.8, 79.5, 113.4, 118.6, 121.8, 124.9, 128.4, 136.0, 150.5. IR: 659.6, 753.5, 1058.8, 1087.6, 1263.6, 1291.8, 1413.6, 1692.5, 1686.7, 2947.0, 3090.8, 3154.1, 3235.4, 3333.2 cm-1.
Compound 2h: 1H NMR (d 6-DMSO): δ = 3.21 (t, J = 4.8 Hz, 2 H), 4.52 (t, J = 4.8 Hz, 2 H), 6.97 (d, J = 7.6 Hz, 1 H), 7.00 (t, J = 7.6 Hz, 1 H), 7.09 (d, J = 7.6 Hz, 1 H), 7.17 (t, J = 7.6 Hz, 1 H), 8.83 (s, 1 H). 13C NMR: δ = 34.5, 68.1, 119.4, 123.1, 126.2, 127.7, 130.3, 136.0, 157.2. IR: 679.7, 741.9, 756.5, 1058.4, 1090.9, 1277.5, 1339.7, 1420.6, 1682.3, 3102.0, 3238.0 cm-1.