319432-08-1Relevant articles and documents
Furan ring opening-indole ring closure: Synthesis of furo[2′, 3′:3,4]-cycloheota[1,2-b]indolium chlorides
Butin, Alexander V.,Smirnov, Sergey K.,Stroganova, Tatyana A.
, p. 623 - 628 (2007/10/03)
A new synthetic approach to furo[2′,3′:3,4]cyclohepta[1,2-b] indolium chlorides is elaborated starting from 2-acetylaminoaryldifurylmethanes or 2-aminoaryldifurylmethanes under treatment with methanolic HCl solution. The reaction proceeds in three steps: recyclization, intramolecular cyclization, and disproportionation. In this case the furan ring takes part in building up both pyrrole and seven-membered rings. The same salts can be obtained directly from 2-acetylaminobenzaldehydes and 2-methylfuran under similar conditions without isolation of corresponding 2-acetylaminoaryldifurylmethanes.