Synthesis 2018; 50(10): 2001-2008
DOI: 10.1055/s-0036-1591923
paper
© Georg Thieme Verlag Stuttgart · New York

Facile Access to 3-Unsubstituted Tetrahydroisoquinolonic Acids via the Castagnoli–Cushman Reaction

Natalia Guranova
Saint Petersburg State University, Saint Petersburg 199034, Russian Federation   Email: m.krasavin@spbu.ru
,
Dmitry Dar’in
Saint Petersburg State University, Saint Petersburg 199034, Russian Federation   Email: m.krasavin@spbu.ru
,
Mikhail Krasavin*
Saint Petersburg State University, Saint Petersburg 199034, Russian Federation   Email: m.krasavin@spbu.ru
› Author Affiliations
This research was supported by the Russian Science Foundation (project grant 14-50-00069).
Further Information

Publication History

Received: 22 November 2017

Accepted after revision: 08 January 2018

Publication Date:
27 February 2018 (online)


Abstract

Hitherto undescribed 3-unsubstituted tetrahydroisoquinolonic acids (isolated as their respective methyl esters) were accessed for the first time by the uncatalyzed, thermally promoted Castagnoli–Cushman reaction (CCR) of homophthalic anhydride (HPA) and a series of 1,3,5-triazinanes. The moderate yields observed in some cases are most likely associated with a persistent impurity also formed in these reactions. The new scaffold is expected to find novel medicinal utility (compared to the traditional CCR adducts) because it lacks a substituent at the 3-position.

Supporting Information