Synthesis of Coumarines and 4H-Chromenes through the Reaction oftert-Butyl Isocyanide and Dialkyl Acetylenedicarboxylates in Presence of 2-Hydroxybenzaldehydes

Abstract

An effective route to novel coumarines and 4Hchromenes is described. This involves the reaction of tert-butyl isocyanide and dialkyl acetylenedicarboxylates in the presence of 2hydroxybenzaldehydes.

Reaction Between 7-Hydroxy Coumarin, Alkyl Isocyanides and Dialkyl Acetylenedicarboxylate: Synthesis of 4H-Chromenes and 1-Azabuta-1,3-dienes

“…The reactions of 1-azadienes with various chiral dienophiles, leads to substituted pyridines [10], and substituted 4Hchromenes are a new class of anti-cancer compounds [11]. 2-Amino-4H-chromenes have been of interest because of their biological activity [12] and some methods have been reported for their synthesis [13][14][15][16][17][18][19][20]. As part of our current studies [21][22][23][24][25][26] on the development of new routes to heterocyclic systems, we now report an efficient synthetic route to 2-amino-4Hchromenes (4) using alkyl isocyanides (1), 7-hydroxycoumarin (2) and alkyl acetylenedicarboxylate (3) (Scheme 1).…”

Microwave assisted synthesis of 2-amino-6-methoxy-4H-benzo[h]chromene derivatives

“…Recently, several methods for the synthesis of 2-aminochromenes and 2-aminobenzochromenes have been described [10,39,40]. Various catalysts such as piperidine [41][42][43][44], morpholine [45], CTACl (Cetyltrimethylammonium chloride) [46], or CTABr (Cetyltrimethylammonium bromide) [47], o-quinone methides (o-QMs) [48,49] and alumina [50] have been used for the preparation of 2-aminochromenes and 2-aminobenzochromenes.…”

ChemInform Abstract: Reaction of tert‐Butyl Isocyanide with Alkyl Propiolates in the Presence of α‐Chloroketones.

“…The reactivity of isocyanides as a nucleophilic carbene towards acetylenic esters is well documented [1][2][3][4][5][6]. The initially formed zwitterionic intermediate can be trapped by a variety of electrophiles and proton donors for synthesis of heterocyclic compounds [7][8][9][10][11][12][13]. The most widely used isocyanide-based reactions were carried out for synthesis of g-iminolactones using an electron-deficient ketone [14][15][16][17][18].…”