Metal-free one-pot synthesis of 1,3-diazaheterocyclic compounds via I₂-mediated oxidative C–N bond formation

Abstract

A one-pot I2-mediated annulation reactionof substrates containing diamino groups and aldehydes has been developed via oxidative C−N bond formation. This general and environmentally benign synthetic approach provides a facile access to a variety of 1,3-diazaheterocyclic compounds, including quinazolinones, benzimidazoles, and cyclic amidines.

One‐Pot Synthesis of Quinazolin‐4(3H)‐ones through Anodic Oxidation and the Related Mechanistic Studies

“…Compound 5 ab was isolated through a silica gel column chromatography (PE: EtOAc from 5:1 to 2:1) as a white solid (38 mg, 81% yield, m.p. 239–241 °C) which is a known compound and the characterization data are in accordance with the literature; 1 H NMR (400 MHz, DMSO‐ d 6 ) δ 12.49 (br, s, 1H), 8.16 (d, J =7.6 Hz, 1H), 8.12 (d, J =8.0 Hz, 2H), 7.86–7.82 (m, 1H), 7.74 (d, J =8.0 Hz, 1H), 7.54–7.50 (m, 1H), 7.36 (d, J =8.0 Hz, 2H), 2.40 (s, 3H); 13 C NMR (100 MHz, DMSO‐ d 6 ) δ 162.8, 152.7, 149.3, 141.9, 135.0, 130.4, 129.6, 128.1, 127.9, 126.8, 126.3, 121.4, 21.5.…”

Crystal structure of 3-amino-2-hydroxy-6-methoxybenzamide hydrate, C16H22N4O7

“…For instance, aminobenzylamides are widely used as anti-cancer drugs, anti-inflammatory analgesics and antilipemic drugs in the field of medicine, and as insecticides and fungicides in the field of pesticides [7]. Additionally, aminobenzylamides can also be used to synthesize quinazolinone, aminobenzene, benzotriazinone and other chemicals with important application value in organic synthesis [8,9]. Although 3-amino-2-hydroxy-6-methoxybenzamide is a known compound, its single crystal structure has not been reported yet.…”

Auto‐Tandem Catalysis with Ruthenium: From o‐Aminobenzamides and Allylic Alcohols to Quinazolinones via Redox Isomerization/Acceptorless Dehydrogenation

“…2‐Pentylquinazolin‐4(3H)‐one (3 ad) . White solid, 84% yield (91 mg); mp 153–154 °C; 1 H NMR (500 MHz, DMSO‐d 6 ) δ 12.15 (br s, 1H), 8.06 (d, J =7.9 Hz, 1H), 7.75 (t, J =7.7 Hz, 1H), 7.58 (d, J =8.1 Hz, 1H), 7.43 (t, J =7.5 Hz, 1H), 2.60–2.57 (t, J =7.6 Hz, 1H), 1.75–1.69 (m, 2H), 1.34–1.29 (m, 4H), 0.88–0.85 (t, J =7.2 Hz, 3H); 13 C { 1 H} NMR (125 MHz, DMSO‐d 6 ) δ 161.9, 157.5, 148.9, 134.1, 126.7, 125.8, 125.6, 120.8, 34.5, 30.7, 26.5, 21.8, 13.8.…”