3D model (JSmol)
CompTox Dashboard (EPA)
|Melting point||165 °C (329 °F; 438 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
4-Phenyl-1,2,4-triazoline-3,5-dione (PTAD) is an azodicarbonyl compound. PTAD is one of the strongest dienophiles and reacts rapidly with dienes in Diels-Alder reactions. The most prominent use of PTAD was the first successful synthesis of prismane in 1973.
The compound was first synthesized in 1894 by Johannes Thiele and O. Stange. The oxidation of 4-Phenylurazol with lead tetroxide in sulfuric acid yielded small quantities of the substance. It took until 1971 when a practical synthesis was published. The synthesis starts from hydrazine and diethyl carbonate. The product of this step is reacted with phenyl isocyanate and subsequently transformed to the 4-Phenylurazol. Cyclization and subsequent oxidation yields PTAD (6).
- Korobitsyna, I. K.; Khalikova, A. V.; Rodina, L. L.; Shusherina, N. P. (1983). "4-Phenyl-1,2,4-triazoline-3,5-dione in organic synthesis (review)". Chemistry of Heterocyclic Compounds. 19 (2): 117–136. doi:10.1007/BF00506417.
- Katz T. J., Acton N. (1973). "Synthesis of Prismane". Journal of the American Chemical Society. 95 (8): 2738–2739. doi:10.1021/ja00789a084.
- Thiele, J.; Stange, O. (1894). "Ueber Semicarbazid". Justus Liebigs Annalen der Chemie. 283 (1–2): 1–43. doi:10.1002/jlac.18942830102.
- Cookson, R. C. (1971). "4-Phenyl-1,2,4-triazole-3,5-dione" (PDF). Organic Syntheses: 121. doi:10.1002/0471264180.os051.30. ISBN 0471264229. Also Organic Syntheses, Coll. Vol. 6, p.936 (1988)