95883-99-1Relevant academic research and scientific papers
AZO DIENOPHILES. DIELS-ALDER REACTIONS OF 4-PHENYL-1,2,4-TRIAZOLE-3,5-DIONE AND 5-PHENYLPYRAZOL-3-ONE WITH FUNCTIONALISED DIENES
Johnson, Matthew P.,Moody, Christopher J.
, p. 71 - 74 (2007/10/02)
4-Phenyl-1,2,4-triazole-3,5-dione (PTAD) undergoes a Diels-Alder reaction with a variety of functionalised dienes.The adduct (9) from 2,3-bis(iodomethyl)butadiene gives, on treatment with zinc-copper couple, the diene 2,3,5,6,7,8-hexahydro-6,7-dimethylene-2-phenyl-1H-triazolo-pyridazine-1,3-dione (10) which then reacts with dienophiles in a tandem Diels-Alder reaction.The unsymmetrical azo dienophile, 5-phenylpyrazol-3-one (3), reacts regioselectively with 1-acetoxy-butadiene to give, after hydrolysis, the alcohol 5,8-dihydro-8-hydroxy-3-phenyl-1H-pyrazolo-pyridazin-1-one (19).
