Synthesis of 6-bromo-2-(o-aminophenyl)-3-amino-Quinazolin-4(3H)-one

A mixture of 6-bromo-2-(o-thiadiaminephenyl)-3-thiadiamine-Quinazolin-4(3H)-one (0.037M, 16.095gm) and fused sodium acetate (0.074M, 6.068gm) was taken in absolute alcohol (300ml) and refluxed for 10 hrs. The bulk of the solvent was reduced to about one third by distilling off the solvent under reduced pressure. Ice cold water was then added to the content. The precipitate so obtained was filtered and washed with distilled water. Rectified spirit was used for recrystallization. m.p.- 202-208OC, yield-85%, Rf = 0.69, IR (cm-1): 1506 υ (C=N str. of the ring), 679 υ (C-S-C str. of the ring). 1H NMR: 11.78 (s, 1H of –NH), 3.36 (s, 2H of -CH2), 3.75 (s, 2H of –CH2), 7.36-7.80 (m, 5H of –ArH), 8.08-8.18 (d, 2H of –ArH).

Synthesis of 6-bromo-2-(o-thiadiaminephenyl)-3-thiadiamine-quinazoline-4(3H)-one

AB - The synthesis of quinazolinone derivatives was achieved from 2-iodobenzamide derivatives and various benzylamines, allylamine, and cinnamylamine derivatives through a one-pot copper-catalyzed reaction. In this reaction, the amine component (benzylamine/allylamine/cinnamylamine) is N-arylated with 2-iodobenzamide derivatives through Ullman coupling, followed by an intramolecular C-H amidation in the presence of copper catalyst. Copper-catalyzed tandem-Ullman N-alkylation and intramolecular C-H amidation reaction protocol for the synthesis of 2-phenylquinazolinone and quinazolinone derivatives from N-substituted 2-iodo-benzamides and benzylamines, allyl, and cinnamylamine is achieved.


Synthesis of Novel Quinazolinone Derivatives[J].

Quinazolinone derivatives are the important inter-mediate of a series of drugs.

Quinazolinone is a versatile lead molecule for designing potential bioactive agents. Imines (Schiff bases) and their reaction products are an interesting class of organic compounds being studied over the years and reported to possess a wide spectrum of biological activities such as antimicrobial 10, 11 antioxidant 12, cytotoxic 13 and anticonvulsant 14. They are formed by simple condensation of amine and aldehyde in alcoholic medium to form an azomethine linkage.


Synthesis of novel quinazolinone and fused …

RESULTS & DISCUSSION: The compounds SRN 3, 4 and 9 possessing 4-chloro, 4-methyl substitution and thiophene side chain linked to quinazolinone moiety through imine group have shown activity at a concentration of 12.5 µg/ml, while other derivatives have shown activity above 50 µg/ml. the compound SRN2 which possess 2-chlorophenyl substitution at 2nd position of quinazolinne moiety and has thiophene ring system in the side chain has shown significant activity (3.125 µg/ml), highlighting the effect of substitutions on the quinazolinone moiety for their biological property. Hence these compounds shall be exploited further for their antitubercular activity to attain a potential pharmacophore.

Synthesis of novel quinazolinone and fused quinazolinones

Rajasekaran S, Rao G and Niranjan HS: Synthesis and Antitubercular Activity of Some Substituted 2, 3-Substituted Quinazolinone Analogs. Int J Pharm Sci Res. 3(11); 4394-4397.

Quinazolinone is a heterocyclic chemical compound

In recent years, there is a tremendous increase of drug resistant pathogens, leading to the design and development of newer antitubercular agents. A series of 2-(substituted-phenyl)-1,3-benzoxazin-4-ones and 3-amino-2-(substituted-phenyl)quinazolin-4(3H)-ones were synthesized by the reaction of substituted benzoyl chloride with anthranilic acid and 2- (substituted phenyl)-1,3-benzoxazin-4-one with hydrazine hydrate in absolute alcohol respectively. The title compounds 2-substituted phenyl-3-(thiophen-2-ylmethyleneamino) quinazolin-4(3H)-ones and 2-(substituted phenyl)-3-(1-(furan-2-yl)ethylideneamino) quinazolin-4(3H)-ones were obtained by reacting 3-amino-2-(substituted phenyl) quinazolin-4(3H)-one with thiophene-2-carboxaldehyde and 2-acetyl furan respectively. The title compounds have been characterized by UV, IR, 1H-NMR and Mass spectra. The synthesized compounds have been evaluated for their antitubercular activity. Few of the compounds exhibited significant antitubercular while other compounds showed moderate activity.

Copy the following to cite this article: Nahad M

The synthesis of quinazolinone derivatives was achieved from 2-iodobenzamide derivatives and various benzylamines, allylamine, and cinnamylamine derivatives through a one-pot copper-catalyzed reaction. In this reaction, the amine component (benzylamine/allylamine/cinnamylamine) is N-arylated with 2-iodobenzamide derivatives through Ullman coupling, followed by an intramolecular C-H amidation in the presence of copper catalyst. Copper-catalyzed tandem-Ullman N-alkylation and intramolecular C-H amidation reaction protocol for the synthesis of 2-phenylquinazolinone and quinazolinone derivatives from N-substituted 2-iodo-benzamides and benzylamines, allyl, and cinnamylamine is achieved.