Cannizzaro reaction of 2-chloro-3-formylquinolines and its synthetic utility for 2-acetylfuro[2,3-b]quinolines: The alkaloid analogues

Abstract

Cannizzaro reaction of 2-chloro-3-formylquinolines was investigated under two different conditions. Under both conditions, redox and methoxylation proceeded simultaneously and gave 2-methoxy-3-formylquinolines, 2-methoxyquinolin-3-yl-methanols and 2-methoxyquinoline-3-carboxylic acids. The synthesized 2-methoxy-3-formylquinolines were then condensed with acetone in the presence of sulphuric acid to give 4-(2-methoxy-quinolin-3-yl)-but-3-en-2-ones which in turn were bromocyclized and dehydrobrominated to get 2-acetylfuro[2,3-b]quinolines.

Robust synthesis of linear and angular furoquinolines using Rap–Stoermer reaction

“…Previously we also reported the synthesis of 2-benzoylfuro[2,3-b]quinolines 14 and 2-acetylfuro[2,3-b]-quinolines. 15 In a continuation of our attempts to access this class of compounds, we herein report an efficient methodology for the synthesis of linear 4-phenylfuro[2,3-b]-quinolines and angular N-methylfuro [3,2-c]quinolines with amide, ester, and ketone groups as substituents at position 2 via the Rap-Stoermer reaction. 16 The Rap-Stoermer reaction has been already applied in the synthesis of linear 2-substituted furo[2,3-b]quinolines by utilizing 3-formyl-2-hydroxyquinolines and α-halocarbonyl compounds.…”