Categories: Synthesis of N-Heterocycles > benzo-fused N-Heterocycles >
Synthesis of 2,3-dihydroquinazolinones
The use of a readily available Sc(III)-inda-pybox as the catalyst enabled an enantioselective synthesis of 2,3-dihydroquinazolinones (DHQZs) via a metal catalyzed asymmetric intramolecular amidation of an imine.
M. Prakash, V. Kesavan, Org. Lett., 2012, 14, 1896-1899.
An L-proline nitrate assisted protocol enables the construction of 2,3-dihydroquinazolin-4(1H)-ones. The catalyst can be recovered and is reusable.
S. P. Bahekar, N. D. Dahake, P. B. Sarode, H. S. Chandak, Synlett, 2015, 26, 2575-2577.
Fluorescent carbon dots are an effective and recyclable carbocatalyst for the synthesis of 2,3-dihydroquinazolinon-4(1H)-one derivatives and aza-Michael adducts under mild reaction conditions. This nanoscale form of carbon may serve as an alternative catalyst for important acid catalyzed organic transformations.
B. Majumdar, S. Mandani, T. Bhattacharya, D. Sarma, T. K. Sarma, J. Org. Chem., 2017, 82, 2097-2106.
The use of [Ce(l-Pro)2]2 (Oxa) as recyclable heterogeneous catalyst enables the preparation of 2-aryl-2,3-dihydroquinazolin-4(1H)-one derivatives from anthranilamide and several aldehydes under mild conditions in ethanol at 50-55°C. The catalyst can be recycled and reused three times without significant loss of catalytic activity.
R. Katla, R. Chowrasia, C. D.G. da Silva, A. R. de Oliveira, B. F. dos Santos, N. L. C. Domingues, Synthesis, 2017, 49, 5143-5148.
Macroporous Amberlyst A26 OH catalyzes a selective hydration of nitriles to primary amides as well as a base-catalyzed synthesis of 2-substituted 4(1H)-quinazolinones via reaction of 2-aminobenzonitrile with carbonyl compounds in H2O-EtOH.
F. Tamaddon, F. Pouramini, Synlett, 2014, 25, 1127-1131.
A transition-metal-free reaction of 2-aminobenzonitriles with aldehydes in the presence of KOtBu provides dihydroquinazolinones in high yields at room temperature. The method is also compatible with ketones for the synthesis of 2,2-disubstituted dihydroquinazolinones.
T. Ghosh, I. Mandal, S. J. Basak, J. Dash, J. Org. Chem., 2021, 86, 14695-14704.
A copper-catalyzed one-pot reaction of 2-nitrobenzonitriles and various carbonyl compounds in the presence of diboronic acid as a reductant provides 2,3-dihydroquinazolin-4(1H)-ones with good functional-group tolerance in good yields under mild conditions.
Q. Liu, Y. Sui, Y. Zhang, K. Zhang, Y. Chen, H. Zhou, Synlett, 2020, 31, 275-279.
A cationic Ru-H complex is a highly effective catalyst for a mild deaminative coupling reaction of 2'-hydroxyaryl ketones with simple amines to form 3-substituted flavanone products. The analogous deaminative coupling reaction of 2-aminobenzamides with branched amines directly formed 3,3-disubstituted quinazolinone products.
K. Gnyawali, P. T. K. Arachchige, C. S. Yi, Org. Lett., 2022, 24, 218-222.
Copper-catalyzed cascade cyclization reactions between alkenyl boronic esters and N-H-based nucleophiles enable new approaches for one-pot assembly of azacycles. Following Chan-Evans-Lam C-N couplings, cyclization processes either afford dihydroquinazolin-4-ones as hydroamination products or quinolines as aromatization products in good yields.
Y. Li, Z. Cao, Z. Wang, L. Xu, Y. Wei, Org. Lett., 2022, 24, 6554-6559.
The reaction between isatoic anhydride, primary amines, and benzylic alcohols in the presence of HBr in DMSO at 80°C affords 2,3-dihydroquinazolin-4(1H)-ones in excellent yields via a metal-free oxidative C(sp3)-N coupling process.
N. R. E. Sheikhi, P. R. Ranjbar, Synlett, 2018, 29, 912-917.
Self-assembly of phosphatidylcholine in water creates liposomal nanoreactors for environmentally friendly synthesis of hydroquinazolinones by two- or three-component reactions, without the use of an extra catalyst or solvent. The reaction medium can be recycled.
F. Tamaddon, M. KazemiVernamkhasti, Synlett, 2016, 27, 2510-2514.
Utilizing a recyclable tartaric acid-SDS catalyst system help to achieve a green synthesis of 2,3-dihydro/spiroquinazolin-4(1H)-ones via three-component cyclocondensation reaction of isatoic anhydride, amines and aldehydes/ketones. Mechanochemical activation at room temperature lead to significant improvement on previously described methods for the synthesis of such compounds even in large-scale reactions.
R. Sharma, A. K. Pandey, P. M. S. Chauhan, Synlett, 2012, 23, 2209-2214.