UV-Light-Induced Dehydrogenative N-Acylation of Amines with 2-Nitrobenzaldehydes To Give 2-Aminobenzamides

Abstract

A simple, mild, green and efficient method for the synthesis of 2-aminobenzamides was highly desired in organic synthesis. Herein, we developed an efficient, one-pot strategy for the synthesis of 2-aminobenzamides with high yields irradiated by UV light. 32 examples proceeded successfully by this photo-induced protocol. The yield reached up to 92%. The gram scale was also achieved easily. This building block could be applied in the preparation of quinazolinones derivatives. Amino acid derivatives could be employed smoothly at room temperature. Finally, a plausible mechanism was proposed.

Application of N,N-Dimethylethanolamine as a One-Carbon Synthon for the Synthesis of Pyrrolo[1,2-a]quinoxalines, Quinazolin-4-ones, and Benzo[4,5]imidazoquinazolines via [5 + 1] Annulation

“…2-Amino-N-(4-bromobenzyl)benzamide (3q). 23 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 146.9, 135.4, 130.0, 127.6 (q, J = 4.0 Hz), 127.2 (q, J = 33.0 Hz), 126.4, 124.1 (q, J = 3.3 Hz), 123.8 (q, J = 270.3 Hz), 114.9, 114.8, 114.4, 108.4; HRMS (ESI-TOF) m/z [M + H] + calcd for C 12 H 8 F 3 N 2 : 237.0634; found: 237.0636.…”

“…2-Amino-N-(4-bromobenzyl)benzamide (3q). 23 White solid. M p 133−135 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 7.48 (d, J = 8.4 Hz, 2 H), 7.32 (d, J = 7.6 Hz, 1 H), 7.26−7.18 (m, 3 H), 6.70 (d, J = 8.4 Hz, 1 H), 6.64 (t, J = 8.0 Hz, 1 H), 6.33 (s, 1 H), 5.55 (s, 2 H), 4.56 (d, J = 6.0 Hz, 2 H).…”

“…1a , 1b , 1e – 1g , 1k , 1m , 3a – 3p , 3r , and 5a are purchased from Bide Pharmatech Ltd. and used without further purification. 1c , 1d , 1h – 1j , 1l , 1n , 1o , 3q , 3s , and 5b – 5d were prepared according to the reported procedures.…”

Continuous Flow Synthesis of Nitrosoarenes via Photochemical Rearrangement of Aryl Imines

“… 12 Furthermore, 2-nitrobenzaldehyde, which we utilize as the starting material to prepare the corresponding nitrophenylimines, is a recognized actinometric compound, and its photochemical reactivity has been examined in diverse studies. 13 Other related photochemical transformations include the reduction of nitro groups to form anilines 14 or the synthesis of 2-aminobenzamides 15 ( Scheme 1 b). The latter transformation was achieved by exciting nitrobenzaldehydes with secondary amines under UV light.…”