Synthesis of 9-ethyl[1,2,5]selenadiazolo[3,4-h]quinolones by the application of modified Gould-Jacobs reaction to N-ethyl-2,1,3-benzoselenadiazol-4-amine

Abstract

An effective method for the synthesis of N-ethyl-2,1,3-benzoselenadiazolamines 11 and 15 has been described. Modified Gould-Jacobs reaction of N-ethylbenzoselenadiazol-4-amine 15 provided 9-ethylselenadiazoloquinolone derivatives 2 and 19 in high yields. Acid-promoted ring closure of enamine 18c unexpectedly afforded completely deacetylated product -9-ethylselenadiazoloquinolone 2. Identical product was obtained by ethylation of selenadiazolo [3,4-h]quinolone 1 and by basic hydrolysis of ethyl ester 19b followed by thermal decarboxylation of the corresponding acid 20.

Gas-phase synthesis of 3-carboethoxy-quinolin-4-ones. A comprehensive computational mechanistic study to uncover the dark side of the Gould–Jacobs reaction

“…6 The last one involves a condensation (Claisen condensation 7 ) followed by an intramolecular cyclization (Camps cyclization 8 ) known under the name of Gould-Jacobs (G-J) reaction from 1939. 9 Since its rst application, this reaction started to be one of the most commonly used methodologies to obtain different quinolones 10 and quinolone-fused compounds as selenadiazoloquinolones, 11,12 pyrimidopyrrolopyrimidines, 13 pyridoquinoxalines, 14 etc.…”