On April 30, 1992, Suzuki, Tsuneo; Tanemura, Kiyoshi; Horaguchi, Takaaki; Shimizu, Takahachi; Sakakibara, Tohru published an article.SDS of cas: 53724-96-2 The title of the article was Benzofuran derivatives. Part 4. Synthesis of benzofurans and 2,3,4,5-tetrahydro-1-benzoxepin-3,5-diones. And the article contained the following:
By treatment of Et 4- or 5-substituted 2-acetylphenoxyacetates I (R = 4-Me, H, 5-Cl, etc.) with potassium hydroxide in dry dioxane, benzofurans II-VII and 2,3,4,5-tetrahydro-1-benzoxepin-3,5-diones VIII were obtained. The relative yields of benzofurans II-VII and 2,3,4,5-tetrahydro-1-benzoxepin-3,5-diones VIII varied with the types of 4- or 5-substituents. The electron-donating 4-methoxy group favored the formation of benzoxepins. On the other hand, electron-withdrawing substituents such as the 4-nitro group favored the formation of benzofurans. When esters I were treated with sodium amide, 2,3-dihydrobenzofurans II were obtained exclusively regardless of 4- or 5-substituents. The experimental process involved the reaction of Ethyl 6-methoxy-3-methylbenzofuran-2-carboxylate(cas: 53724-96-2).SDS of cas: 53724-96-2
The Article related to acetylphenoxyacetate cyclization, phenoxyacetate acetyl cyclization, benzofuran, tetrahydrobenzoxepindione, benzoxepindione tetrahydro, Heterocyclic Compounds (One Hetero Atom): Areno- and Diarenofurans and other aspects.SDS of cas: 53724-96-2
Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem