Pyrido[2′1′:2,3]imidazo[4,5‐c]isoquinoline and the alkylation of pyrido[2′,1′:2,3]imidazo[4,5‐c]isoquinolin‐5(6H)‐one

Abstract

The reaction of 2‐aminopyridine, o‐phthaldehydic acid and potassium cyanide gave pyrido[2′,1′:2,3]imidazo[4,5‐c]isoquinolin‐5(6H)‐one, which upon treatment with propargylbromide, yielded both O and N alkylated products. 2‐Aminopyridine, o‐phthaldehyde and potassium cyanide gave 1‐cyano‐2‐(2‐pyridyl)isoindole which rearranged in acid to give the previously unreported parent pyrido[2′,1′:2,3]imidazo[4,5‐c]isoquinole. Structures were confirmed using uv, ir, nmr and x‐ray spectroscopy.

Synthesis and evaluation of the antiproliferative activity of novel isoindolo[2,1-a]quinoxaline and indolo[1,2-a]quinoxaline derivatives

“…This cyano-substituted isoindole 9 was also preliminary prepared by a Strecker-type synthesis between 2-fluoroaniline and o-phthalodicarboxaldehyde in water and in the presence of potassium cyanide and sodium hydrogensulfite 23 . Treatment of 9 with potassium hydroxide in tert-butanol at 80°C led directly to the tetracyclic lactam 4d involving selective hydrolysis to amide, which was able to carry out intramolecular displacement of aromatic fluorine through an anionic ring closure [24][25][26][27] .…”

One-pot three-component synthesis of pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolines using Fe3O4@SiO2–OSO3H as an efficient heterogeneous nanocatalyst

“…18 A few procedures have been reported in the literature for the synthesis of pyrido[2 0 ,1 0 :2,3]imidazo [4,5-c]isoquinolines. [19][20][21][22] The most common method for their preparation is the reaction of 2-formylbenzoic acid or its esters, pyridin-2-amines, and KCN, 19 TMSCN/KF 20 or isocyanides. 21,22 In connection with our recent studies on magnetic nanocatalysts in multicomponent reactions, [23][24][25][26][27][28][29] herein, we wish to report the synthesis of pyrido[2 0 ,1 0 :2,3]imidazo [4,5-c]…”

Three-Component Combinatorial Synthesis of a Substituted 6H-Pyrido[2‘,1‘:2,3]imidazo- [4,5-c]isoquinolin-5(6H)-one Library with Cytotoxic Activity

“…To the best of our knowledge, only a single example for the formation of this heterocyclic system by a three-component reaction is reported in the literature, namely, the synthesis of pyrido[2‘,1‘:2,3]imidazo[4,5- c ]isoquinolin-5(6 H )-one ( V ) by condensation of 2-aminopyridine, phthaldehydic acid, and potassium cyanide, with only 35% yield. Moreover, the R group at position 6 could be introduced by alkyl halides in a sodium hydride−DMF mixture method, but it is reported that under these conditions an 84:16 mixture of O- and N -alkylated products VI and VII was obtained (Scheme ), which makes it hard to diversify the library.

1 Synthesis of Pyrido[2‘,1‘:2,3]imidazo[4,5- c ]- isoquinolin-5(6 H )-one and its Alkylation Products

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