Triazolinediones (TADs)

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]

Scheme 1

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