New conditions for synthesis of (±)‐2‐monosubstituted and (±)‐2,2‐disubstituted 2,3‐dihydro‐4(1H)‐quinazolinones from 2‐nitro‐ and 2‐aminobenzamide

Abstract

An efficient synthesis of (±)‐2‐monosubstituted and (±)‐2,2‐disubstituted 2,3‐dihydro‐4(1H)‐quinazolinones has been developed using a dissolving metal reduction‐condensative cyclization strategy. Treatment of 2‐nitrobenzamide and an aldehyde or ketone with iron powder in refluxing acetic acid affords high yields of the title compounds. More complex ring systems are available by incorporating additional reactive functionality γ to the carbonyl of the aldehyde or ketone substrate. The scope and limitations of the process along with optimized procedural details are presented. The same target molecules are also accessible by reaction of 2‐aminobenzamide with aldehydes and ketones in refluxing acetic acid. J. Heterocyclic Chem., (2011).

5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolines. Message 4. Spirocompounds with [1,2,4]triazolo[1,5-c]quinazolines moieties. The synthesis and spectral

“…ных анилинов с циклоалканонами (циклопентаноном, циклогексаноном) позволила получить продукты би-нуклеофильного присоединения, а именно спироконденсованные соединения с [1,2,4]триазоло [1,5-c] (1-R-пиперидоном-4, дигидротиофен-3(2H)-оном, дигидро-2H-пиран-4(3H)-оном, дигидро-2H-тиопиран-3(4H)-оном) протекает без особенностей с образованием соответствующих 2'-арил-6'H-спиро [1,2,4] триазоло [1,5-c]хиназолинов. Также без особенностей протекает реакция с 5-R-1H-индол-2,3-дионом (изати-ном) и его N-замещенными производными с образованием арил-2'-арил-6'H-спиро[(индол-3,5'-[1,2,4] триазоло [1,5-c] Development and optimization of the existing synthetic methods of quinazoline and triazolo [c]quinazoline spiroderivatives are among important tasks of organic, bioorganic and medicinal chemistry.…”

“…Reactions of [5+1]-cyclocondensation based on interactions of 1,5-binucleophiles with carbonyl compounds (cycloalkanones, 1-R-4-piperidone and others) can serve as an approach for construction of spiro compounds. Thus, the authors used 2-nitrobenzamide [4], 2-aminobenzamide and its derivatives [2,[5][6][7][8], or 1H-benzo[d] [1,3]oxazine-2,4-dione [9] for the synthesis of 3'-R-1'-R-1'Hspiro[cycloalkane-1,2'-quinazoline]-4'(3'H)-ones, oximes of 2-aminoacetophenone [3] for the synthesis of 4'-methyl-1' ,2'-dihydrospiro[cycloalkane-1,2'-quinazoline]-3-oxides, and 2-(aminomethyl)aniline [10,11] for the synthesis of 3' ,4'-dihydro-1'H-spiro[cyclohexane-1,2'-quinazoline]. However, only one publication was devoted to the synthesis of spiro [piperidine-4,5' (6'H)- [1,2,4]triazolo [1,5-c]quinazolines], in which 2-(1H-1,2,4-triazol-5-yl)aniline was used to form the systems mentioned [2].…”

“…Thus, the authors used 2-nitrobenzamide [4], 2-aminobenzamide and its derivatives [2,[5][6][7][8], or 1H-benzo[d] [1,3]oxazine-2,4-dione [9] for the synthesis of 3'-R-1'-R-1'Hspiro[cycloalkane-1,2'-quinazoline]-4'(3'H)-ones, oximes of 2-aminoacetophenone [3] for the synthesis of 4'-methyl-1' ,2'-dihydrospiro[cycloalkane-1,2'-quinazoline]-3-oxides, and 2-(aminomethyl)aniline [10,11] for the synthesis of 3' ,4'-dihydro-1'H-spiro[cyclohexane-1,2'-quinazoline]. However, only one publication was devoted to the synthesis of spiro [piperidine-4,5' (6'H)- [1,2,4]triazolo [1,5-c]quinazolines], in which 2-(1H-1,2,4-triazol-5-yl)aniline was used to form the systems mentioned [2]. Based on the above mentioned facts the aim of this work is to study the reactivity of [2-(3-aryl-1H-1,2,4-triazol-5-yl)phenyl]amines that are insufficiently studied as 1,5-binucleophiles in [5+1]-cyclocondensation reactions with cycloalkanones, heterocyclonones, isatines, and it can be one of the synthetic approaches for formation of the unstudied 2'-aryl-6'H-spiro [1,2,4]triazolo [1,5-c]quinazolines.…”

“…However, only one publication was devoted to the synthesis of spiro [piperidine-4,5' (6'H)- [1,2,4]triazolo [1,5-c]quinazolines], in which 2-(1H-1,2,4-triazol-5-yl)aniline was used to form the systems mentioned [2]. Based on the above mentioned facts the aim of this work is to study the reactivity of [2-(3-aryl-1H-1,2,4-triazol-5-yl)phenyl]amines that are insufficiently studied as 1,5-binucleophiles in [5+1]-cyclocondensation reactions with cycloalkanones, heterocyclonones, isatines, and it can be one of the synthetic approaches for formation of the unstudied 2'-aryl-6'H-spiro [1,2,4]triazolo [1,5-c]quinazolines.…”

Pyrrolo[1,2-a]quinazolines: synthesis and biological properties

“…Isoindolo[2,1-a]quinazolines were synthesized 102,[108][109][110][111][112][113][114][115][116] and studied for a broad range of medicinal applications including TNF-α inhibitors 110 antibacterial and antifungal activity 116 or CNS depressants. …”