Synthesis of quinazolin-4(3 H )-ones and 1,2-dihydroquinazolin-4(3 H )-ones with the aid of a low-valent titanium reagent

Synthesis of methylene- and epoxy-bridged spiroquinazolinones

“…Other methodologies too have been employed, for example with isatoic anhydride 16,17 or anthranylhydrazide 18 as starting compound. For the preparation of spiro-1,2-dihydroquinazolin-4(3H)ones, a new method, the reductive cyclization of 2-nitrobenzamides with carbonyl compounds, was introduced by Shi et al 19,20 Results and Discussion 22 it is presumed that the cis diastereoisomer was synthetized.…”

2-Aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1<i>H</i>)-ones as substrates for the synthesis of 2,6,8-triarylquinazolin-4-ones

“…These compounds are generally accessible via the condensation of isatoic anhydride or anthranilamide derivatives with aldehydes or ketones using p-toluenesulfonic acid [5], HCl [6], samarium iodide [7], TiCl 4 -Zn [8], NH 4 Cl [9], boric acid [10], cerium(IV) ammonium nitrate [11], iodine [12], gallium(III) triflate [13] or β-cyclodextrin [14] as catalysts. Molecular iodine catalyzed condensation of isatoic anhydride with benzaldehyde derivatives in the presence of NH 4 OAc in ethanol under reflux, on the other hand, previously afforded the 2-arylquinazolin-4(3H)-ones exclusively or along with the 2,3-dihydroquinazolin-4(1H)-ones depending on the ratio of iodine used [15].…”

Silica Supported Zinc (II) Chloride (SiO2-ZnCl2) as an Efficient Catalyst for the Eco-Friendly Synthesis of 2,3-Dihydroquinazolin-4(1H)-Ones

“…In particular dihydroquinazolin-4(1H)-one scaffold were found as a core unit in a number of biologically active compounds that they include anticancer, antidituric, anticonvulsant activities. [1][2][3][4][5][6][7][8] Thus, extensive efforts have been exerted on developing methodology for the synthesis of dihydroquinazolin-4(1H)-one derivative. Several numbers of synthetic strategies are known for the preparation of substituted dihydroquinazolin-4(1H)-ones.…”