RESEARCH ON IMIDAZOISOQUINOLINE DERIVATIVES. 3. ACYLATION OF 2-SUBSTITUTED IMIDAZOISOQUINOLINES

Article abstract of DOI:10.1007/BF00523080

The acylation of 2-alkyl, 2-aryl, and 2-hetaryl derivatives of imidazo<2,1-a>isoquinoline was studied. 3-Acetyl-substituted derivatives of this system were synthesized by the action of acetic anhydride on 2-arylimidazoisoquinolines in the presence of magnesium perchlorate.Under similar conditions 2-hetaryl derivatives are acetylated not only in the 3 position but also in the hetaryl ring. 3-Acetyl-2-methylimidazoisoquinoline, which is not formed as a result of direct acylation, was synthesized by indirect methods, viz., on the basis of 1-aminoisoquinoline and 3-chloroacetylacetone or from 1-acetamidoisoquinoline and bromoacetone.The compounds obtained are extremely resistant to hydrolysis, give the usual reactions at the carbonyl group, condense with aromatic aldehydes, and undergo bromination to give 3-bromo- and 3-dibromoacetyl derivatives.