Metal free synthesis of functionalized 1-aryl isoquinolines via iodine mediated oxidative dehydrogenation and ring opening of lactam in isoindoloisoquinolinones

Abstract

A facile and convenient method for the synthesis of substituted 2-(isoquinolin-1-yl)benzoic acids from isoindoloisoquinolinones in the presence of molecular iodine under sealed tube condition at 100 • C has been developed. This methodology involves the oxidative dehydrogenation and ring opening of hydroxy lactam/methoxy lactam to furnish the 2-(isoquinolin-1-yl)benzoic acids. Some of these acids are successfully cyclized to furnish the azabenzanthrone derivatives, the potential precursors for the synthesis of menisporphine alkaloids and daurioxoisoaporphines.

Oxoisoaporphines and Aporphines: Versatile Molecules with Anticancer Effects

“…Many studies have reported the synthesis of oxoisoaporphine derivatives [46,56,57,63,[65][66][67][68]. Most synthesis methods follow a similar process starting with 3-(β-dialkoxyarylethylamino)phthalides with polyphosphoric acid [66,69], β-phenylethylamines with phthalic anhydride, or substituted β-phenylethylamines with benzoyl chloride [44,45,67,68]. The reaction is a Bischler-Napieralski reaction or a variant [70].…”

“…For example, Castro-Castillo et al described a synthesis route from 1-Aza-2,3-dihydro-5-methoxybenzanthrone following these steps: (1) nitration, (2) catalytic oxidation using air, and (3) selective reduction of the nitro groups to obtain lakshminine, as shown in Scheme 1. [66,69], β-phenylethylamines with phthalic anhydride, or substituted β-phenylethylamines with benzoyl chloride [44,45,67,68]. The reaction is a Bischler-Napieralski reaction or a variant [70].…”

Copper‐Catalyzed Synthesis of 13‐Aminoisoquinolino[2,1‐a]perimidine‐12‐carboxylates via α‐Arylation with a High Chemoselectivity

“…), and it is an antianemic drug that has been used in the phase III clinical trials . In view of their importance in medicinal chemistry, a lot of novel procedures have been developed for the synthesis of perimidine and isoquinoline derivatives in recent years.…”