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Synlett 2006(13): 2154-2155
DOI: 10.1055/s-2006-948178
DOI: 10.1055/s-2006-948178
SPOTLIGHT
© Georg Thieme Verlag Stuttgart · New York
Triazolinediones (TADs)
Further Information
Publication History
Publication Date:
09 August 2006 (online)
Biographical Sketches
Introduction
4-Substituted-1,2,4-triazoline-3,5-diones (TADs, 2) were first synthesized by Thiele in 1894. [1] These compounds were prepared via oxidation of urazoles (1, Scheme 1). [2] Urazoles and their oxidation products (TADs) are commercially available. [3] Recently, several heterogeneous systems have been reported for the oxidation of urazoles to their corresponding triazolinediones. [4] Triazolinediones are red or pink crystalline solids which are very reactive and able to participate in a wide range of reactions such as [2+2] and [4+2] cycloadditions, ene reactions, and electrophilic aromatic substitutions, etc. [5-7]
Abstracts
(A) Reaction of 2,6-dimethoxyphenol (1) with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) produces the arylated urazole 2 which can be oxidized to the stable dienone ylide 3 upon treatment with either tert-butyl hypochlorite or excess PTAD. When ylide 3 is formed in situ and treated with Meldrum"s acid and triethylamine, the orange p-quinone methide 4 is obtained. [8] | |
(B) Triazolinediones react with ketones and after oxidation give triazolinedione ylides. The resulting ylides, usually generated in situ, undergo condensations with enolate species to form acylated olefins in synthetically useful yields. The tri- and tetraacylolefins produced by this method are susceptible to subsequent Michael addition of enolates. [9] | |
(C) PTAD oxidizes alcohols to aldehydes or ketones at room temperature in a few hours with high yields. Dry benzene is a convenient solvent, from which the phenylurazole separates during the reaction. [10] | |
(D) 4-Substituted-1,2,4-triazoline-3,5-diones (R = Me or Ph) react stereospecifically with trans-cyclooctene 1 to give addition products 2, 3, and 4. [11] | |
(E) Dehydrogenation of various annulated dihydropyridazines occured with 4-phenyl-1,2,4-triazoline-3,5-dione as dehydrogenating agent. [12] | |
(F) 4-Substituted-1,2,4-triazoline-3,5-diones were used as effective and recyclable oxidizing agents for the oxidation of both 1,4-dihydropyridines [13] and 1,3,5-trisubstituted-pyrazolines [14] to their corresponding pyridines and pyrazoles, respectively under mild conditions with moderate to excellent yields. Simple oxidation procedures of urazoles regenerate TADs. [13] [14] |
- 1
Thiele J.Strange O. Justus Liebigs Ann. Chem. 1894, 283: 1 -
2a
Stickler JC.Pirkle WH. J. Org. Chem. 1966, 31: 3444 -
2b
Mallakpour SE. J. Chem. Educ. 1992, 69: 238 - 3a These compounds are commercially available from Merck, http://www.merck.com
-
3b
Chandrasekhar B.Kumar GB.Mallela S.Bhirud SB. Org. Prep. Proced. Int. 2004, 36: 469 -
4a
Zolfigol MA.Chehardoli GA.Mallakpour SE. Synth. Commun. 2003, 33: 833 -
4b
Zolfigol MA.Nasr-Isfahani H.Mallakpour SE.Safaiee M. Synlett 2005, 761 -
4c
Zolfigol MA.Ghorbani-Vaghei R.Mallakpour SE.Chehardoli GA.Choghamarani AG.Yazdi HA. Synthesis 2006, 1631 -
5a
Mallakpour SE.Butler GB.Aghabozorg H.Palenik GJ. Macromolecules 1985, 18: 342 -
5b
Vougioukalakis GC.Orfanopoulos M. Synlett 2005, 713 -
5c
Dover J.Sheridan RS. Tetrahedron Lett. 1990, 31: 1961 -
6a
Adam W.Glaser J.Peters K.Prein M. J. Am. Chem. Soc. 1995, 117: 9190 -
6b
Chen JS.Houk KN.Foote CS. J. Am. Chem. Soc. 1998, 120: 12303 -
7a
Tsuda T.Chujo Y.Nishi S.Tawara K.Saegusa T. J. Am. Chem. Soc. 1980, 102: 6384 -
7b
Mallakpour SE.Butler GB. J. Polym. Sci., Part A: Polym. Chem. 1989, 27: 217 - 8
Wilson RM.Chantarasiri N. J. Am. Chem. Soc. 1991, 113: 2301 - 9
Wilson RM.Hengge AC.Ataei A.Ho DM. J. Am. Chem. Soc. 1991, 113: 1240 - 10
Cookson RC.Stevens IDR.Watts CT. Chem. Commun. 1966, 744 - 11
Poon THW.Park SH.Elemes Y.Foote CS. J. Am. Chem. Soc. 1995, 117: 10468 - 12
Klindert T.Seitz G. Synth. Commun. 1996, 26: 2587 - 13
Zolfigol MA.Choghamarani AG.Shahamirian M.Safaiee M.Mohammadpoor-Baltork I.Mallakpour SE.Abdollahi-Alibeik M. Tetrahedron Lett. 2005, 46: 5581 - 14
Zolfigol MA.Azarifar D.Mallakpour SE.Mohammadpoor-Baltork I.Maleki B.Forghaniha A.Abdollahi-Alibeik M. Tetrahedron Lett. 2005, 4: 833
References
- 1
Thiele J.Strange O. Justus Liebigs Ann. Chem. 1894, 283: 1 -
2a
Stickler JC.Pirkle WH. J. Org. Chem. 1966, 31: 3444 -
2b
Mallakpour SE. J. Chem. Educ. 1992, 69: 238 - 3a These compounds are commercially available from Merck, http://www.merck.com
-
3b
Chandrasekhar B.Kumar GB.Mallela S.Bhirud SB. Org. Prep. Proced. Int. 2004, 36: 469 -
4a
Zolfigol MA.Chehardoli GA.Mallakpour SE. Synth. Commun. 2003, 33: 833 -
4b
Zolfigol MA.Nasr-Isfahani H.Mallakpour SE.Safaiee M. Synlett 2005, 761 -
4c
Zolfigol MA.Ghorbani-Vaghei R.Mallakpour SE.Chehardoli GA.Choghamarani AG.Yazdi HA. Synthesis 2006, 1631 -
5a
Mallakpour SE.Butler GB.Aghabozorg H.Palenik GJ. Macromolecules 1985, 18: 342 -
5b
Vougioukalakis GC.Orfanopoulos M. Synlett 2005, 713 -
5c
Dover J.Sheridan RS. Tetrahedron Lett. 1990, 31: 1961 -
6a
Adam W.Glaser J.Peters K.Prein M. J. Am. Chem. Soc. 1995, 117: 9190 -
6b
Chen JS.Houk KN.Foote CS. J. Am. Chem. Soc. 1998, 120: 12303 -
7a
Tsuda T.Chujo Y.Nishi S.Tawara K.Saegusa T. J. Am. Chem. Soc. 1980, 102: 6384 -
7b
Mallakpour SE.Butler GB. J. Polym. Sci., Part A: Polym. Chem. 1989, 27: 217 - 8
Wilson RM.Chantarasiri N. J. Am. Chem. Soc. 1991, 113: 2301 - 9
Wilson RM.Hengge AC.Ataei A.Ho DM. J. Am. Chem. Soc. 1991, 113: 1240 - 10
Cookson RC.Stevens IDR.Watts CT. Chem. Commun. 1966, 744 - 11
Poon THW.Park SH.Elemes Y.Foote CS. J. Am. Chem. Soc. 1995, 117: 10468 - 12
Klindert T.Seitz G. Synth. Commun. 1996, 26: 2587 - 13
Zolfigol MA.Choghamarani AG.Shahamirian M.Safaiee M.Mohammadpoor-Baltork I.Mallakpour SE.Abdollahi-Alibeik M. Tetrahedron Lett. 2005, 46: 5581 - 14
Zolfigol MA.Azarifar D.Mallakpour SE.Mohammadpoor-Baltork I.Maleki B.Forghaniha A.Abdollahi-Alibeik M. Tetrahedron Lett. 2005, 4: 833