1412898-44-2Relevant academic research and scientific papers
Mechanistic and exploratory investigations into the synthesis of 1,3,5-triaroylbenzenes from 1-aryl-2-propyn-1-ones and 1,3,5-triacetylbenzene from 4-methoxy-3-buten-2-one by cyclotrimerization in hot water in the absence of added acid or base
Iwado, Tatsuya,Hasegawa, Keiya,Sato, Toshiyuki,Okada, Masaki,Sue, Kiwamu,Iwamura, Hiizu,Hiaki, Toshihiko
, p. 1949 - 1954 (2013)
Neat 1-phenyl- and 1-(p-tolyl)-2-propyn-1-ones (1 and 1′, respectively) were heated in water without any additive at 150 °C for 2 h to give 1,3,5-tribenzoyl- and 1,3,5-tri-(p-toluoyl)benzenes (2 and 2′, respectively) in 74 and 52% yields, respectively. The crossed reactions of 1 with the enolate of p-toluoylacetaldehyde (3′) and 1′ with the enolate of benzoylacetaldehyde (3) were carried out to give unsymmetrically substituted 1-toluoyl-3,5-dibenzoylbenzene (Ph2Tol) and 1,3-ditoluoyl-5-benzoylbenzene (PhTol2), respectively, corroborating the previously proposed reaction mechanism in which 3 and 3′ that are formed by rate-determining nucleophilic attack of HO- on 1 and 1′ or its conjugate acids formed by subsequent protonation would serve as a common intermediate for the formation of 2, 2′ and the acetophenone derivatives as byproducts. When 4-methoxy-3-buten-2-one (4) was heated in hot pure water without any additive at 150 °C for 30 min, 1,3,5-triacetylbenzene (5) was obtained in an isolated yield of 77% just by removing water by filtering the crystalline product from the cooled reaction mixture. The reaction did not take place in the absence of water. Slow decompositions of 5 in water set in at the temperature of 300 °C for 30 min.
