the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil
A novel catalytic system is reported for the construction of quinazolinones via the carbon-supported acid-catalyzed cascade coupling of isatoic anhydrides with amides and aldehydes. Subsequent selective hydrosilylation of the quinazolinones using a hydrogen-transfer strategy was also explored to provide dihydroquinazolines with structural diversity. The developed methodology proceeds with a broad substrate
Rapid assembly of quinazolinone scaffold via copper-catalyzed tandem reaction of 2-bromobenzamides with aldehydes and aqueous ammonia: application to the synthesis of the alkaloid tryptanthrin
作者:Shenghai Guo、Yan Li、Li Tao、Wenwen Zhang、Xuesen Fan
DOI:10.1039/c4ra10799c
日期:——
procedure for the preparation of 2-substituted and 2,3-disubstituted quinazolinones was achieved through copper-catalyzed tandem reaction of 2-bromobenzamides with aldehydes and aqueous ammonia under air. Control experimental results indicated that this tandem reaction is triggered by a copper-catalyzed direct amination of 2-bromobenzamides with aqueous ammonia, followed by cyclocondensation and oxidative
An ultraviolet absorbent represented by the following Formula (1) or (6):
wherein, Het
1
represents a monovalent five- or six-membered aromatic heterocyclic residue; X
a
and X
b
each independently represent a heteroatom; Y
a
to Y
c
each independently represent a heteroatom or a carbon atom; the ring formed from carbon atom, X
a
, X
b
, Y
a
to Y
c
may have a double bond at any position and has at least one fused ring;
wherein, Het
6
represents a monovalent five- or six-membered aromatic heterocyclic residue; X
6a
and X
6b
each independently represent a heteroatom; Y
6a
, Y
6b
and Y
6c
each independently represent a heteroatom or a carbon atom; L
6
represents a bi- to octa-valent connecting group; n is an integer of 2 or more, and m is an integer of 0 or more.