Synthesis of 1-Formyl-1,2-dihydroquinoline Derivatives by a Lewis Acid-Catalyzed Cyclization of o-(1-Hydroxy-2-alkenyl)phenyl Isocyanides

Abstract

An efficient route to 1-formyl-1,2-dihydroquinolines 6 is described based on the BF3-catalyzed cyclization of o-(1-hydroxy-2-alkenyl)phenyl isocyanides 4, which can be prepared feasibly by the reaction of N-(o-acylphenyl)formamides 1 with alkenylmagnesium bromides 2 followed by treatment of the resulting hydroxy formamides 3 with phosphorous oxychloride.

Synthesis, Structural Characterization, and Catalytic Activity of Flower Like ZnO Nanostructures

“…Formamides exhibit potential applications in the synthesis of pharmaceutical compounds such as fluoroquinolines, 1 substituted aryl imidazoles, 2 1,2-dihydroquinolines, 3 nitrogenbridged heterocycles 4 etc., Formamides also find its applications in Vilsmeier formylation, 5 preparation of isocyanide, 6 Lewis base organic transformation, allylation and reduction reactions. Formyl group is highly useful as an amino protecting group in peptide synthesis.…”

“…Hence, extensive research efforts were devoted to develop the time and cost efficient strategic techniques for the synthesis of various amide derivatives. [3][4][5] However, the reported N-formylation methods exhibited certain bottlenecks such as sensitive to atmospheric moisture, toxic formylating agents, high temperature, prolonged reaction times for completion, severe reaction conditions, by-products, thermal instability of products etc., [3][4][5] which collectively faded the large scale applications of amide derivatives. To eradicate the aforementioned significant issues, the reaction of formic acid with amine derivatives has been proposed.…”

Synthesis of N-Formylation of Amines using Various Ion Exchanged Forms of Zeolite-A as Catalysts

“…They have been used in the synthesis of some pharmaceutically important compounds such as Fluoroquinolones [1], 1, 2 dihydro quinolones [2] and Nitrogen based heterocyclic compounds [3]. In Lewis bases, its main importance is to catalyze some important reactions such as allylation [4] and hydrosilyation of carbonyl compounds [5] Formamides Act as useful reagent in Vilsmeier Formylation reaction [6].…”

Poly(N,N′-dichloro-N-ethyl-benzene-1,3-disulfonamide, N,N,N′,N′-tetrachlorobenzene-1,3-disulfonamide, poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide, and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide catalyzed formylation of amines and alcohols using ethyl formate under microwave irradiation

“…N-Formyl compounds have been widely used in organic synthesis as protecting group of amines [1], an intermediate for mono methylated amines from primary amines [2], catalyst for allylation, or reduction [3]. They have been also widely used in the synthesis of pharmaceutically important compounds such as fluroqninolones [4], substituted aryl imidazoles [5], 1,2-dihydroqninolines [6] and nitrogen bridged heterocycles [7], etc. Thus, various formylating methods have been reported for the preparation of formylated compounds.…”