Simple and scalable electrosynthesis of 1H-1-hydroxy-quinazolin-4-ones

Abstract

Cathodic synthesis provides sustainable access to 1-hydoxy- and 1-oxy-quinazolin-4-ones from easily accessible nitro starting materials. Mild reaction conditions, inexpensive and reusable carbon-based electrode materials, an undivided electrochemical setup, and constant...

Dual Roles of Supporting Electrolytes in Organic Electrosynthesis

“…nitrobenzamide substrates 51 are reduced to the corresponding hydroxylamine intermediates 48 using sulfuric acid as a supporting electrolyte (Scheme 11c). Subsequently, an intramolecular condensation occurs, leading to 1 H ‐1‐hydroxy‐quinazolin‐4‐ones 52 with excellent yields [44] . A 100‐fold scale‐up was proven on a 15 mmol batch, revealing the robustness and scalability of this protocol.…”

“…Subsequently, an intramolecular condensation occurs, leading to 1H-1-hydroxy-quinazolin-4-ones 52 with excellent yields. [44] A 100-fold scale-up was proven on a 15 mmol batch, revealing the robustness and scalability of this protocol.…”

“…b Intermolecular follow‐up reaction with alcohol solvent to form 2‐alkyl‐4(3H)‐quinazolinones [43] . c Intramolecular reaction of nitrobenzamides to 1 H ‐1‐hydroxy‐quinazolin‐4‐ones [44] . d Intramolecular reaction of Zincke‐type salts to pyrido[1,2‐a]benzimidazoles [45] …”

Simple electrochemical synthesis of cyclic hydroxamic acids by reduction of nitroarenes

“…14,15 Based on previous work on the direct electrochemical reductive synthesis of N-O heterocycles, a synthetic protocol for the selective and scalable synthesis of 2H,4H-4-hydroxy-1, 4-benzoxazin-3-ones was established, providing direct access to this highly promising class of compounds. [16][17][18][19] For the optimisation of the electrolytic conditions, methyl 2-(2-nitrophenoxy)acetate (6a) was prepared in a single step. The initial electrolytic conditions were chosen based on previous reductions.…”

“…14,15 Based on previous work on the direct electrochemical reductive synthesis of N–O heterocycles, a synthetic protocol for the selective and scalable synthesis of 2 H ,4 H -4-hydroxy-1,4-benzoxazin-3-ones was established, providing direct access to this highly promising class of compounds. 16–19…”