A novel synthesis of some 1,4‐phenylene‐bis‐heterocyclic carboxamide derivatives

Abstract

magnified image N,N′‐(1,4‐phenylene)bis(3‐oxo‐3‐phenylpropanamide) 1 reacts with DMFDMA in refluxing toluene to afford N,N′‐(1,4‐phenylene)bis(2‐benzoyl‐3‐(dimethylamino)acrylamide) 2. Compound 2 reacts with a twofold excess of the active methylene reagents 3a, 3b, 3c to afford the pent‐2‐enediamide derivatives 7 and 8a, 8b, respectively. Compounds 7 and 8a could be cyclized to afford the same compound N,N′‐(1,4‐phenylene)bis(5‐cyano‐6‐oxo‐2‐phenyl‐1,6‐dihydropyridine‐3‐carboxamide) 9a while 8b was cyclized to afford the 6‐thioxo analogue 9b. Compound 2 reacts with hydrazine derivatives 10a, 10b in refluxing ethanol/piperidine to afford the hydrazinylacrylamide derivatives 11a, 11b, which have been cyclized to the corresponding N,N′‐(1,4‐phenylene)bis(1H‐pyrazole‐4‐carboxamide) derivatives 12a, 12b, respectively. Compound 2 reacts also with urea derivatives 13a, 13b, 13c in refluxing ethanol/piperidine to afford the N,N′‐(1,4‐phenylene)bis(2‐benzoyl‐3‐substituted‐acrylamide) derivatives 14a‐c, which could be cyclized into N,N′‐(1,4‐phenylene)bis(6‐phenyl‐1,2‐dihydropyrimidine‐5‐carboxamide)‐2‐oxo; 2‐thioxo or 2‐imino derivatives 15a, 15b, 15c, respectively. J. Heterocyclic Chem., (2009).

Bis-enaminones as versatile precursors for terheterocycles:synthesis and reactions

“…Refluxing the latter in ethanolic sodium ethoxide solution furnished its cyclization and afforded the product 112a identical with that one obtained by reaction of 42 with malononitrile under the same reaction conditions. 27 …”

Synthetic applications of benzothiazole containing cyanoacetyl group

“…In continuation of our program and following our previous interest [15][16][17][18][19][20] in the synthesis of new heterocyclic compounds of anticipated biological activity, it has been found that cyanoacetylation of 2-(benzo[d]thiazol-2-yl)acetonitrile, 3, will lead to an excellent building block for the synthesis of target compounds. Thus, when 3 was treated with cyanoacetic acid in the presence of acetic anhydride, it afforded the corresponding 2-(benzo[d]thiazol-2-yl)-3-oxopentanedinitrile, 4, as tested by thin-layer chromatography (TLC) (Scheme 2).…”

Synthesis of Some Novel 1,4‐Phenylene‐bis‐thiazolyl Derivatives and Their Anti‐hypertensive α‐blocking Activity Screening

“…Within the frame of this program we have recently reported many syntheses of several novel bisheterocyclic compounds [4][5][6].…”