Synthesis of novel 2,3-substituted quinazolin-4-ones by condensation of alkyl or aromatic diamines with 5-(N-arylimino)-4-chloro-5H-1,2,3-dithiazoles

Crystal Structure and Solid-State Packing of 4-Chloro-5H-1,2,3-dithiazol-5-one and 4-Chloro-5H-1,2,3-dithiazole-5-thione

The crystal structure and solid-state packing of 4-chloro-5H-1,2,3-dithiazol-5-one and two polymorphs of 4-chloro-5H-1,2,3-dithiazole-5-thione were analyzed and compared to structural data of similar systems. These five-membered S,N-rich heterocycles are planar with considerable bond localization. All three structures demonstrate tight solid-state packing without voids which is attributed to a rich network of short intermolecular electrostatic contacts. These include S^δ+…N^δ−, S^δ+…O^δ−, S^δ+…Cl^δ− and S^δ+…S^δ− interactions that are well within the sum of their van der Waals radii (∑_VDW). B3LYP, BLYP, M06, mPW1PW, PBE and MP2 were employed to calculate their intramolecular geometrical parameters, the Fukui condensed functions to probe their reactivity, the bond order, Bird Index and NICS(1) to establish their aromaticity.

Unexpected Insertion of Nitrogen into a C-C Bond: Access to 2,3-Disubstituted Quinazolinone Scaffolds

A novel, practical, highly efficient, and transition metal free nitrogen insertion reaction for the synthesis of 2,3-disubstituted quinazolinone derivatives was developed. Diverse functionalized 3-indolinone-2-carboxylates and nitrosoarenes with a wide range of substituted nitrosobenzenes, nitrosopyridines, dibenzofuranyl, or dibenzothienyl nitroso compounds worked smoothly to give 2,3-disubstituted quinazolinone derivatives in good to excellent yields (69-98%). A gram-scale reaction was achieved, and an afloqualone analogue was synthesized under the mild reaction conditions.

Palladium-catalyzed cascade reactions in aqueous media: synthesis and photophysical properties of pyrazino-fused quinazolinones

A convenient, efficient, and direct approach toward the synthesis of pyrazino-fused quinazolinone frames has been developed. The photophysical properties of 3e with the AIE effect were investigated.

Facile synthesis of 1,4-benzodiazepine-2,5-diones and quinazolinones from amino acids as anti-tubercular agents

A family of 1,4-benzodiazepine-2,5-diones and quinazolinones with diverse substituents at C-3 position are synthesized by novel, simple and convenient methodology using H₂PtCl₆as catalyst and were all screened for anti-TB activity.

Recent advances in 4(3H)-quinazolinone syntheses

The new routes and strategies for the synthesis of valuable 4(3H)-quinazolinones have been summarized.