A green one‐pot pseudo‐five‐component sequential protocol for the synthesis of novel 6,6′‐(arylmethylene)bis(benzo[a]phenazin‐5‐ol) derivatives

Abstract

A simple and efficient synthesis of novel 6,6′‐(arylmethylene)bis(benzo[a]phenazin‐5‐ol) derivatives has been developed via a sequential one‐pot, two‐step, pseudo‐five‐component tandem reaction starting from 2‐hydroxynaphthalene‐1,4‐dione, o‐phenylenediamine, and aromatic aldehydes in the presence of 2‐aminopyridine as co‐catalyst and p‐TsOH as catalyst at 90°C under solvent‐free conditions. This sequential green process offers several advantages, such as operational simplicity, high yield, low cost, easy handling, clean reactions, absence of any tedious work‐up, and purification of products by non‐chromatographic methods.

A review on lawsone-based benzo[a]phenazin-5-ol: synthetic approaches and reactions

“…Then, intermediate 265 tautomerizes to the keto form 266, which undergoes intramolecular cyclization via an oxygen atom attacking to the carbonyl group and elimination of water to afford the desired product 260. 109 Next, an efficient and versatile protocol for the synthesis of hybrid polycyclic quinolinobenzo six membered fused rings and three contiguous stereogenic centers. 110 Recently, Safaei-Ghomi and his group synthesized phenazinpyrimidines 271 in 82-95% yields via one-pot fourcomponent reaction of 3, 2a, aldehydes and 6-amino-1-3dimethyluracil using Co 3 O 4 /ZnO@N-GQDs@SO 3 H nanocomposite as a robust heterogeneous catalyst under ultrasonic irradiations in EtOH for 10-15 min.…”

“…Then, intermediate 265 tautomerizes to the keto form 266 , which undergoes intramolecular cyclization via an oxygen atom attacking to the carbonyl group and elimination of water to afford the desired product 260 . 109…”

Synthetic strategies of phenazine derivatives: A review

“…Very recently, Olyaei and co-workers [82] furnished a remarkable and efficient strategy for preparation of S C H E M E 1 Synthetic route and structures of the compounds 1-10 S C H E M E 2 Synthetic route and structures of the compounds 8-10 in the presence of copper(II) acetate as a catalyst highly functionalized benzo[a]phenazine derivatives (34)(35)(36)(37)(38)(39)(40)(41)(42). As shown in Scheme 7, this method employed a domino, one-pot, two-step, and multicomponent condensation reaction between o-phenylenediamine, 2-hydroxynaphthalene-1,4-dione, and aromatic aldehydes in the presence of p-TsOH as catalyst and 2-aminopyridine as co-catalyst under solvent-free condition.…”

“…Very recently, Olyaei and co‐workers [82] furnished a remarkable and efficient strategy for preparation of highly functionalized benzo[a]phenazine derivatives (34–42 ). As shown in Scheme 7, this method employed a domino, one‐pot, two‐step, and multicomponent condensation reaction between o‐phenylenediamine, 2‐hydroxynaphthalene‐1,4‐dione, and aromatic aldehydes in the presence of p ‐TsOH as catalyst and 2‐aminopyridine as co‐catalyst under solvent‐free condition.…”

MOFs impregnados con agua y otros disolventes para evaluar sus propiedades en la captura selectiva de gases de efecto invernadero y reacciones pseudo-multicomponentes

“…arilmetilen)bis-(benzo[a]fenazina-5-oles),[183] utilizando 2-hidroxinaftaleno-1,4-diona (205), o-fenilendiamina (206), aldehídos aromáticos 207, con ácido p-toluensulfónico (p-TsOH) como catalizador y 2-aminopiridina (208) como co-catalizador, mediante una pseudo-5CR bajo un proceso tándem. De acuerdo con el mecanismo de reacción propuesto por los autores (Esquema 28), 205 se tautomeriza a 209, que luego reacciona con benceno-1,2diamina 206 para producir benzo[a]fenanzin-5-ol 210.…”