A novel and expedient approach to new heterocycles containing benzothiophene, benzothieno[2,3-d]pyrimidine and coumarin moieties

Synthesis and antimicrobial activity of 5-hydroxymethyl- 8-methyl-2-(N-arylimino)-pyrano[2,3-c]pyridine-3-(N-aryl)-carboxamides

“…However, in our recent studies we showed that the products of substitution at 2-imino nitrogen can also be formed upon the reaction of 2-iminocoumarin-3-carboxamides with nucleophiles, such as aromatic amines. 8,12 In this work, we observed that their 7-aza analogs can react with aromatic amines in a similar manner. Reaction of 4a-j with several substituted anilines in boiling acetic acid led to formation of N-arylimino derivatives 5{1-35}.…”

Synthesis of substituted 3‐(5‐amino‐[1,3,4]thiadiazol‐2‐yl)‐2H‐pyrano[2,3‐c]pyridin‐2‐ones

“…We have obtained a series of 3-heteroaryl-2H-b e n z o p y r a n -2 -o n e s using acid-catalyzed intermolecular recyclization of the reactive intermediates produced by reaction of 2-imino-2H-1-benzopyran-3-carboxamides with o rt h o-s u b s t i t u t e d anilines [7], hydrazides of arylcarboxylic acids [8], anthranilic acids derivatives [9] and 2-aminothiophene derivatives [10]. The key benefits of our approach are high reaction yields, efficiency and synthetic convenience.…”

“…H o w e v e r, there are only a few examples in which this method has been used for preparation of 3-substituted 7-azacoumarin derivatives [6]. Here, we report the use of the Knoevenagel reaction for the synthesis of 2H-pyrano [2,3-c]pyridine-3-carboxamides, which appear to be useful intermediates for diverse 3-heteroaryl-7-azacoumarins.Recently, we have developed a novel synthetic approach to 3-substituted coumarins based on a rearrangement of 2-iminocoumarin-3-carboxamides under treatment with dinucleophilic agents as the key step [7][8][9][10]. We have obtained a series of 3-heteroaryl-2H-b e n z o p y r a n -2 -o n e s using acid-catalyzed intermolecular recyclization of the reactive intermediates produced by reaction of 2-imino-2H-1-benzopyran-3-carboxamides with o rt h o-s u b s t i t u t e d anilines [7], hydrazides of arylcarboxylic acids [8], anthranilic acids derivatives [9] and 2-aminothiophene derivatives [10].…”

“…Treatment of 5 with N 4 -s u b s t i t u t e d thiosemicarbazides 6{ 1 -3 5 } in acetic acid at 40-45 °C furnished a library of novel 2H-p y r a n o [ 2 , 3 -c] p y r i d i n e -2 -o n e s 8{ 1 -3 5 } in good yields. It can be suggested that, under the described conditions, the reaction proceeds via a series of species 7a-c and involves a study of recyclization proposed in our recent work [10]. The intermediate 7 a represents a product of direct coupling of imine 5 with the NH 2 -group of Jul-Aug 2004 517 I. O. Zhuravel, S. M. Kovalenko, A. V. Ivachtchenko, V. P. Chernykh, and P. E. Shinkarenko 518…”

Optical properties of new fluorescent iminocoumarins. Part 2. Solvatochromic study and comparison with the corresponding coumarin

“…At a wider scale, coumarin derivatives are intensively used for the colouring or fluorescent whitening of textiles and other materials. In contrast, the neighbouring series of iminocoumarins [4][5][6][7][8][9][10] has surprisingly received very little attention until now. However, iminocoumarins are verhttp://france.elsevier.com/direct/CRAS2C/ C. R. Chimie 9 (2006) [1252][1253][1254][1255][1256][1257][1258][1259] satile compounds, which can be easily modified by substitution on the imino group.…”