Cyclization of 2-Azido-3-(alkyl-N-nitrosoamino)-1,4-naphthoquinones to 1-Alkyl-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione 2-Oxides

Abstract

Thermolysis of 2-azido-3-(alkyl-N-nitrosoamino)-1,4-naphthoquinones gives rise to compounds belonging to a new quinoid fused heterocyclic system, 1-alkyl-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione 2-oxides. R = Me (a), Et (b), i-Bu (c), Bzl (d).

Copper(I)-Catalyzed Nitrosylation/Annulation Cascade of Enaminones with tert-Butyl Nitrite: Access to 1H-1,2,3-Triazole 2-Oxides

“…9 Regioisomers 1,2,3-triazole 1-oxides and 1,2,3triazole 3-oxides could be achieved by the above methods. 1,2,3-Triazole 2-oxides have recently been exhibited antitumor activity, 10 which has aroused the additional interest of chemists. However, regioselective construction of 1,2,3triazoles 2-oxides has been challenging due to the unmanageable regioselectivity of the conventional synthetic reactions.…”

“…However, regioselective construction of 1,2,3triazoles 2-oxides has been challenging due to the unmanageable regioselectivity of the conventional synthetic reactions. Both intramolecular cyclization of azido-nitrosamines 10 and bisnitrosoamines 11 and intermolecular cyclization of diaminopyridines with nitric acid 12 are the usually used methods to access 1,2,3-triazoles 2-oxides (Scheme 1a). Involvement of explosive azides or concentrated acids leads to potential hazards, and multistep processes result in poor efficiency.…”

“…It was observed that BHT completely inhibited the reaction, and only a 28% yield was obtained for 3a in the presence of TEMPO (eq 4). The radical-trapping species TEMPO-NO (10) was detected in the reaction mixture by HRMS determination, indicating a potential radical pathway for the reaction (see the SI).…”

Hibridização molecular de núcleos naftoquinônicos, chalcônicos e triazólicos através de reações click

“…A metodologia de síntese da 2-azido-1,4-naftoquinona foi baseada no trabalho de Radaeva e colaboradores. 51…”