Aerobic Oxybromination of Phenols Catalyzed by Sodium Nitrite under Mild Conditions

Abstract

An efficient catalytic system for oxybromination of phenols under mild conditions has been developed, which utilizes sodium nitrite as the catalyst, dioxygen or air as the terminal oxidant, aqueous hydrobromic acid or molecular bromine as the bromine resource. From both the atom-economic and environmental points of view, the developed protocol is expected to provide a valuable synthetic method for practical applications in laboratory or industry.

Key words

oxybromination - phenols - atom economy - oxygen - ­sodium nitrite

References and Notes

• 1a Ulmann’s Encyclopedia of Industrial Chemistry   6th ed.:  Wiley-VCH; Weinheim: 1998. 
• 1b Larock JRC. Comprehensive Organic Transformations, A Guide to Functional Group Preparation   Wiley; New York: 1997. 
• 2 Butler A. Walker JV. Chem. Rev.  1993,  93:  1937 
• 3a Heravi MM. Abdolhosseini N. Oskooie HA. Tetrahedron Lett.  2005,  46:  8959 
• 3b Kosolapoff GM.
  J. Am. Chem. Soc.  1953,  75:  3596 
• 4a Venkateswarlu K. Suneel K. Das B. Reddy KN. Reddy TS. Synth. Commun.  2009,  39:  215 
• 4b Das B. Venkateswarlu K. Krishnaiah M. Holla H. Tetrahedron Lett.  2006,  47:  8693 
• 4c Ganguly NC. Dutta S. Synthesis  2005,  1103 
• 4d Oberhauser T. J. Org. Chem.  1997,  62:  4504 
• 5 Viroopakshappa J. Jagannadham V. Indian J. Chem., Sect. A: Inorg., Bio-inorg., Phys., Theor. Anal. Chem.  2004,  43:  532 
• 6a Toda F. Schmeyers J. Green Chem.  2003,  5:  701 
• 6b Fuchs B. Belsky Y. Tartakovsky E. Zizuashvili J. Weinman S. J. Chem. Soc., Chem. Commun.  1982,  778 
• 7 Joshi AV. Baidossi M. Mukhopadhyay S. Sasson Y. Org. Process Res. Dev.  2004,  8:  568 
• 8 Barhate NB. Gajare AS. Wakharkar RD. Bedekar AV. Tetrahedron  1999,  55:  11127 
• 9a Narender N. Mohan KVVK. Kulkarni SJ. Raghavan KV. J. Chem. Res., Synop.  2003,  9:  597 
• 9b Narender N. Srinivasu P. Prasad MR. Kulkarni SJ. Raghavan KV. Synth. Commun.  2002,  32:  2313 
• 10a Adibi H. Hajipour AR. Hashemi M. Tetrahedron Lett.  2007,  48:  1255 
• 10b Dewkar GK. Narina SV. Sudalai A. Org. Lett.  2003,  5:  4501 
• 10c Roy SC. Guin C. Rana KK. Matit G. Tetrahedron Lett.  2001,  42:  6941 
• 11a Kikushima K. Moriuchi T. Hirao T. Tetrahedron Lett.  2010,  51:  340 
• 11b Wang J. Wang W. Li JH. Green Chem.  2010,  12:  2124 
• 11c Podgoršek A. Zupan M. Iskra J. Angew. Chem. Int. Ed.  2009,  48:  8424 
• 11d Yang LJ. Zhan L. Stahl SS. Chem. Commun.  2009,  6460 
• 11e Das DP. Parida KM. Catal. Commun.  2006,  7:  68 
• 11f Maurya MR. Saklani H. Agarwal S. Catal. Commun.  2004,  5:  563 
• 11g Narender N. Mohan KVVK. Reddy RV. Srinivasu P. Kulkarni SJ. Raghavan KV. J. Mol. Catal. A: Chem.  2003,  192:  73 
• 11h Choudary BM. Sudha Y. Reddy PN. Synlett  1994,  450 
• 12 Neumann R. Assael I. J. Chem. Soc., Chem. Commun.  1988,  1285 
• 13 Raja R. Ratnasamy P. J. Catal.  1997,  170:  244 
• 14 Menini L. Parreira LA. Gusevskaya EV. Tetrahedron Lett.  2007,  48:  6401 
• 15 Kikushima K. Moriuchi T. Hirao T. Chem. Asian J.  2009,  4:  1213 
• 16 Zhang GF. Liu RH. Xu Q. Ma LX. Liang XM. Adv. Synth. Catal.  2006,  348:  862 

17

Representative Procedure
In a 250 mL Schlenk flask equipped with magnetic stirrer, filled with dioxygen beforehand, was placed phenol (0.4706 g, 5.00 mmol) dissolved in MeCN (10.0 mL) under O₂. Then a 42% aq solution of HBr (1.0125 g, 5.25 mmol) was added to the solution. Next, the NaNO₂ (0.0103 g, 0.15 mmol) was added in one portion, and the system was immediately sealed. The reaction mixture was stirred at 25 ˚C. After the reaction, the solvent was removed under vacuum, and the residue was washed with sat. NaHCO₃ solution and extracted with Et₂O. The organic extract was dried over with anhyd Na₂SO₄. After removing the solvent under vacuum, the residue was purified by column chromatography to afford the desired products, 2- and 4-bromophenol. The yield was 0.7962 g (92%).
4-Bromophenol
^¹H NMR (400 MHz, CDCl₃): δ = 6.70-6.72 (m, 2 H, ArH), 7.31-7.33 (m, 2 H, ArH) ppm. ^¹³C NMR (100 MHz, CDCl₃): δ = 113.0, 117.1, 132.5, 154.2 ppm.
2-Bromophenol
^¹H NMR (400 MHz, CDCl₃): δ = 5.51 (s, 1 H, OH), 6.78-6.83 (m, 1 H, ArH), 7.00-7.04 (m, 1 H, ArH), 7.19-7.25 (m, 1 H, ArH), 7.44-7.47 (m, 1 H, ArH) ppm. ^¹³C NMR (100 MHz, CDCl₃): δ = 110.1, 116.1, 121.7, 129.0, 132.0, 152.0 ppm.