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Synlett 2006(12): 1928-1932  
DOI: 10.1055/s-2006-947339
LETTER
© Georg Thieme Verlag Stuttgart · New York

A New LiBr-Catalyzed, Facile and Efficient Method for the Synthesis of 14-Alkyl or Aryl-14H-dibenzo[a,j]xanthenes and Tetrahydrobenzo[b]pyrans under Solvent-Free Conventional and Microwave Heating

Anil Saini, Sanjay Kumar, Jagir S. Sandhu*
Department of Chemistry, Punjabi University, Patiala 147 002, India
Fax: +91(175)2283073; e-Mail: j_sandhu2002@yahoo.com;
Further Information

Publication History

Received 8 May 2006
Publication Date:
24 July 2006 (online)

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Abstract

An efficient method for the synthesis of 14-alkyl or aryl-14H-dibenzo[a,j]xanthenes and tetrahydrobenzo[b]pyrans under solvent-free conventional and microwave heating using lithium bromide, is described.

Key words

xanthenes - tetrahydrobenzo[b]pyrans - solvent-free - lithium bromide - microwave irradiation

    References and Notes

  • 1 Green GR. Evans JM. Vong AK. In Comprehensive Heterocyclic Chemistry II   Vol. 5:  Katritzky AR. Rees CW. Scriven EFV. Pergamon Press; Oxford: 1995.  p.469 
    Search in Google Scholar
  • 2a Sirkeciolgu O. Talini N. Akar A. J. Chem. Res., Synop.  1995,  502 
  • 2b Ahmad M. King TA. Ko D.-K. Cha BH. Lee J. J. Phys. D: Appl. Phys.  2002,  35:  1473 
    Search in Google Scholar
  • 2c Ion RM. Fara VL. Proc. Indian Acad. Sci.  1999,  107:  825 
    Search in Google Scholar
  • 3a Ion RM. Progr. Catal.  1997,  2:  55 
    Search in Google Scholar
  • 3b Ion RM. Frackowiak D. Planner A. Wiktorowicz K. Acta Biochim. Pol.  1998,  45:  833 
    Search in Google Scholar
  • 4 Hideo T. inventors; Jpn. Tokkyo Koho  JP56005480.  ; Chem. Abstr. 1981, 95, 80922b
  • 5 Lambert RW, Martin JA, Merrett JH, Parkes KEB, and Thomas GJ. inventors; PCT Int. Appl.  WO9706178.  ; Chem. Abstr. 1997, 126, 212377y
  • 6 Poupelin JP. Saint-Ruf G. Foussard-Blanpin O. Narcisse G. Uehida-Ernouf G. Lacroix R. Eur. J. Med. Chem.  1978,  13:  67 
    Search in Google Scholar
  • 7 Callan JF. De Silva P. Magri DC. Tetrahedron  2005,  61:  8551 
    CrossrefSearch in Google Scholar
  • 8a Knight DW. Little PB. Synlett  1998,  1141 
  • 8b Knight DW. Little PB. J. Chem. Soc., Perkin Trans. 1  2001,  14:  1771 
    Search in Google Scholar
  • 9 Jha A. Beal J. Tetrahedron Lett.  2004,  45:  8999 
    CrossrefSearch in Google Scholar
  • 10a Sarma RJ. Baruah JB. Dyes Pigm.  2005,  64:  91 
    CrossrefSearch in Google Scholar
  • 10b Bekaert A. Andrieux J. Plat M. Tetrahedron Lett.  1992,  33:  2805 
    CrossrefSearch in Google Scholar
  • 10c Buechler CA. Cooper DE. Scrudder EO. J. Org. Chem.  1943,  8:  316 
    CrossrefSearch in Google Scholar
  • 11 Papini P. Cimmarusti RE. Gazz. Chim. Ital.  1947,  77:  142 
    Search in Google Scholar
  • 12 Ota K. Kito T. Bull. Chem. Soc. Jpn.  1976,  49:  1167 
    CrossrefSearch in Google Scholar
  • 13 Van Allan JA. Giannini DD. Whitesides TH. J. Org. Chem.  1982,  47:  820 
    CrossrefSearch in Google Scholar
  • 14 Sen RN. Sarkar NN. J. Am. Chem. Soc.  1925,  47:  1079 
    CrossrefSearch in Google Scholar
  • 15a Ono F. Negoro R. Sato T. Synlett  2001,  1581 
    Crossref
  • 15b Pushin AN. Trachentro SE. Martynov IV. Dokl. Akad. Nauk SSSR  1988,  299:  154 
    CrossrefSearch in Google Scholar
  • 15c Seeback D. Thaler A. Blaser D. Ko SY. Helv. Chem. Acta  1991,  74:  1102 
    CrossrefSearch in Google Scholar
  • 15d Prajapati D. Lekhok KR. Sandhu JS. Ghosh AC. J. Chem. Soc., Perkin Trans. 1  1996,  959 
    Crossref
  • 15e Baruah PP. Gadhwal S. Prajapati D. Sandhu JS. Synlett  2002,  1038 
    Crossref
  • 15f Laskar DD. Prajapati D. Sandhu JS. Synth. Commun.  2001,  1427 
    Crossref
  • 16a Firouzabadi H. Karimi B. Eslami S. Tetrahedron Lett.  1999,  4055 
    Thieme Connect
  • 16b Firouzabadi H. Iranpoor N. Karimi M. Synthesis  1999,  58 
    Thieme Connect
  • 17a Kappe CO. Angew. Chem. Int. Ed.  2004,  43:  6250 
    CrossrefSearch in Google Scholar
  • 17b Hayes BL. Aldrichimica Acta  2004,  37:  66 
    CrossrefSearch in Google Scholar
  • 17c Nüchter M. Ondruschka B. Bonrath W. Gum A. Green Chem.  2004,  4:  128 
    CrossrefSearch in Google Scholar
  • 17d Mavanadadi F. Lidstrom P. Curr. Top. Med. Chem.  2004,  4:  773 
    CrossrefSearch in Google Scholar
  • 17e Al-Obeidi F. Austin RE. Okonya JF. Bond DRS. Mini Rev. Med. Chem.  2003,  3:  449 
    CrossrefSearch in Google Scholar
  • 17f Wilson NS. Roth GP. Curr. Opin. Drug Discovery Dev.  2002,  5:  620 
    CrossrefSearch in Google Scholar
  • 17g Lidstrom P. Tierney J. Wathey B. Westman J. Tetrahedron  2001,  57:  9225 
    CrossrefSearch in Google Scholar
  • 18a Laskar DD. Gohain M. Prajapati D. Sandhu JS. New J. Chem.  2002,  193: 
    Search in Google Scholar
  • 18b Sarmah U. Boruah RC. Sandhu JS. Tetrahedron Lett.  2002,  43:  143 
    Search in Google Scholar
  • 18c Laskar DD. Prajapati D. Sandhu JS. Chem. Res., Synop.  2001,  313 
  • 18d Thakuria JA. Baruah M. Sandhu JS. Chem. Lett.  1999,  995 
  • 18e Gadhwal S. Baruah M. Sandhu JS. Synlett  1999,  1573 
  • 18f Karmakar D. Prajapati D. Sandhu JS. J. Chem. Res., Synop.  1998,  382 
  • 18g Borah HN. Boruah RC. Sandhu JS. J. Chem. Res., Synop.  1998,  272 
  • 18h Konwar D. Boruah RC. Sandhu JS. Tetrahedron Lett.  1997,  38:  4267 
    Search in Google Scholar
  • 18i Baruah B. Prajapati D. Baurah A. Sandhu JS. Tetrahedron Lett.  1997,  38:  449 
    Search in Google Scholar
  • 21a Wang XS. Shi DQ. Tu SJ. Yao CS. Synth. Commun.  2003,  33:  119 
    CrossrefSearch in Google Scholar
  • 21b

    Selected Characterization Data. 14-Phenyl-14 H -dibenzo[ a,j ]xanthene (3a, Table 1, Entry 1).
    Mp 184-85 °C. IR (KBr): 3030, 1612, 1242 cm-1. 1H NMR (200 MHz, CDCl3): δ = 6.75 (s, 1 H), 7.10-8.10 (m, 17 H). Anal. Calcd for C27H18O: C, 90.47; H, 5.06. Found: C, 90.55; H, 5.15.
    14-(4-Methoxyphenyl)14- H -dibenzo[ a,j ]xanthene (3c, Table 1, Entry 3).
    Mp 203-04 °C. IR (KBr): 3035, 1621, 1581, 1252. cm-1. 1H NMR (200 MHz, CDCl3): δ = 3.50 (s, 3 H), 6.45 (s, 1 H), 6.73 (d, J = 9.3 Hz, 2 H), 7.36-7.92 (m, 12 H), 8.36 (d, J = 9.3 Hz, 2 H). Anal. Calcd for C28H20O2: C, 86.57; H, 5.19. Found: C, 86.35; H, 5.29.
    14-(3-Bromophenyl)-14- H -dibenzo[ a,j ]xanthene (3d, Table 1, Entry 4).
    Mp 190-92 °C. IR (KBr): 3040, 1613, 1245. cm-1. 1H NMR (200 MHz, CDCl3): δ = 6.62 (s, 1 H), 7.21-20 (m, 16 H). Anal. Calcd for C27H17BrO: C, 74.15; H, 3.92. Found: C, 74.21; H, 3.86. UV (CHCl3): λmax = 245, 266, 335 nm.
    14-(4-Nitrophenyl)-14 H -dibenzo[ a,j ]xanthene (3g, Table 1, Entry 7).
    Mp 309-10 °C. IR (KBr): 3070, 1615, 1540, 1355, 1245. cm-1. 1H NMR (200 MHz, CDCl3): δ = 7.20-7.90 (m, 12 H), 8.15 (d, J = 9.0 Hz, 2 H), 8.55 (d, J = 9.0 Hz, 2 H). Anal. Calcd for C27H17NO3: C, 80.38; H, 4.25; N, 3.47. Found: C, 80.29; H, 4.10; N, 3.55. UV (CHCl3): λmax 245, 259, 335 nm.
    14-(4-Methylphenyl)-14 H -dibenzo[ a,j ]xanthene (3i, Table 1, Entry 9).
    Mp 227-29 °C. IR (KBr): 3038, 1618, 1240 cm-1. 1H NMR (200 MHz, CDCl3): δ = 2.30 (s, 3 H), 6.55 (s, 1 H), 7.15-7.95 (m, 16 H). Anal. Calcd for C28H20O: C, 90.29; H, 5.41. Found: C, 90.41; H, 5.49.
    14-Ethyl-14 H -dibenzo[ a,j ]xanthene (3j, Table 1, Entry 10).
    Mp 112-13 °C. IR (KBr): 3045,2901, 1615, 1221 cm-1. 1H NMR (200 MHz, CDCl3): δ = 0.98 (t, J = 6.1 Hz, 3 H) 1.64 (d, J = 6.1 Hz, 3 H), 5.60 (q, J = 6.1 Hz, 1 H) 7.09-7.97 (m, 12 H). Anal. Calcd for C23H18O: C, 89.00; H, 5.85. Found: C, 89.12; H, 5.76.
    2-Amino-3-cyano-4-phenyl-7,7-dimethyl-5-oxo-4 H -5,6,7,8-tetrahydrobenzo[ b ]pyran (6a, Table 2, Entry 1).
    Mp 232-234 °C. IR (KBr): 3392, 3288, 2934, 2198, 1685, 1601 cm-1. 1H NMR (200 MHz, CDCl3): δ = 0.97 (s, 3 H), 1.04 (s, 3 H), 2.18 (d, J = 14.5 Hz, 1 H), 2.23 (d, J = 14.5 Hz, 1 H), 2.50-2.60 (br s, 2 H), 4.30 (s, 1 H), 6.10 (s, 2 H), 7.20-7.40 (m, 5 H). Anal. Calcd for C18H18N2O2: C, 73.45; H, 6.16; N, 9.52. Found: C, 73.58; H, 6.08; N, 9.40.
    Ethyl-2-Amino-4-phenyl-7,7-dimethyl-5-oxo-4 H -5,6,7,8-tetrahydrobenzo[ b ]pyran Carboxlate (6d, Table 2, Entry 4).
    Mp 191-193 °C. IR (KBr): 3420, 2960, 2925, 1749, 1598, 1358 cm-1. 1H NMR (200 MHz, CDCl3): δ = 1.0 (s, 3 H), 1.06 (s, 3 H), 1.21 (t, J = 7.5 Hz), 2.14 (d, J = 14.0 Hz, 1 H), 2.25 (d, J = 14.0 Hz, 1 H), 2.49 (br s, 2 H), 4.19 (q, J = 7.5 Hz), 4.27 (s, 1 H), 5.84 (s, 2 H), 7.10-7.35 (m, 5 H). Anal. Calcd for C20H23NO4: C, 70.38; H, 6.74; N, 4.11. Found: C, 70.30; H, 6.83; N, 4.07.
    Crossref
19

General Procedure for the Synthesis of 14-Alkyl or Aryl Dibenzo[ a,j ]xanthenes - Method A.
A mixture of aldehyde (2 mmol), β-naphthol (4 mmol) and LiBr (0.3 mmol) were mixed and stirred for 5 min at r.t. and then temperature was raised to 130 °C and maintained for the appropriate time given in Table [1] . After completion of reaction (TLC), the reaction mixture was cooled to r.t. and H2O (20 mL) was added and the mixture stirred for 5 min. The solid thus obtained was filtered and the crude product obtained was purified by recrystallization from EtOH.
Method B.
A mixture of aldehyde (2 mmol,), β-naphthol (4 mmol) and LiBr (0.3 mmol) were irradiated in a domestic microwave oven at 500 W for the appropriate time according to Table [1] . After completion of reaction (TLC), the reaction mixture was cooled to r.t. and H2O (20 mL) was added and the mixture stirred for 5 min. The solid thus obtained was filtered and the crude product obtained was purified by recrystallization from EtOH.

20

General Procedure for the Synthesis of Tetrahydrobenzo[ b ]pyran - Method A.
A mixture of aldehyde (2 mmol,), 5,5-dimethyl-1,3-cyclo-hexanedione (2 mmol), active methylene compound (2 mmol) and LiBr (0.6 mmol) was mixed and stirred for 5 min at r.t. and then heated at 90 °C for the appropriate time given in Table [2] . After completion of reaction (TLC), the reaction mixture was cooled to r.t., H2O (20 mL) was added and the mixture stirred for 5 min. The solid thus obtained was filtered and the crude product obtained was purified by recrystallization from EtOH.
Method B.
A mixture of aldehyde (2 mmol), 5,5-dimethyl-1,3-cyclo-hexanedione (2 mmol), active methylene compound (2 mmol) and LiBr (0.6 mmol) was irradiated in a domestic microwave oven at 500 W for the appropriate time according to Table [2] . After completion of reaction (TLC), the reaction mixture was cooled to r.t., H2O (20 mL) was added and the mixture stirred for 5 min. The solid thus obtained was filtered and the crude product obtained was purified by recrystallization from EtOH.