28873-29-2

Upstream product

• 3004-42-0 5-phenyl-1,3,4-oxadiazole-2(3H)-thione 
• 28144-70-9 anthranilic acid amide 
• 134-20-3 2-carbomethoxyaniline 
• 83717-73-1 C₁₆H₁₅N₃O₃S 
• 613-94-5 benzoic acid hydrazide 
• 16024-82-1 methyl 2-isothiocyanatobenzoate 

Downstream Products

• 28873-45-2 2-phenyl-5H-1,3,4-thiadiazolo<2,3-b>quinazolin-5-one 

Relevant academic research and scientific papers

Ring-Opening Reaction of 1,3,4-Oxadiazolone and 1,3,4-Oxadiazolinethione: Reaction of 2-Phenyl-1,3,4-oxadiazolin-5-one and 2-Phenyl-1,3,4-oxadiazoline-5-thione with Amines

The ring-opening abilities of amines toward 1,3,4-oxadiazolines, 2-phenyl-1,3,4-oxadiazolin-5-one (1a) and 2-phenyl-1,3,4-oxadiazoline-5-thione (1b), were investigated with relation to their basicities or pKb values.Oxadiazolines 1a and 1b were easily reacted with amines such as benzylamine and aniline, but not with p-nitroaniline, to form the corresponding ring-opening adducts.The reactions of both 1a and 1b with o-phenylenediamine produced benzodiazoles with the liberation of benzoylhydrazide, whereas the reactions with o-aminobenzamide furnished quinazolines with the liberation of ammonia. o-Aminophenol and o-aminothiophenol were also reacted with 1a and 1b both of them giving 1,5-dibenzoylcarbohydrazide from 1a and 1,2-dibenzoylhydrazine from 1b.From the conditions affording the corresponding ring-opening adducts or reaction products, the ring-opening abilities of the amines toward 1a and 1b are in good correlation with the strength of their basicities or pKb values.The ring-opening of oxadiazolines were proved to occur with anilines.Therefore, the other reactions are also supposed to proceed via the ring-opening steps.

Synthesis of Substituted N-(2,4-Dioxo-1,2,3,4-tetrahydroquinazolinyl)benzamides and N-(2-Thiono-4-oxo-1,2,3,4-tetrahydroquinazolinyl)benzamides

Substuted N-(2,3-dioxo-1,2,3,4-tetrahydroquinazolinyl)benzamides (3a-g) and substituted N-(2-thiono-4-oxo-1,2,3,4-tetrahydroquinazolinyl)benzamides (4a-g) were synthetized in one step from the reaction of methyl anthranilate with 2-aryl-1,3,4-oxadiazolin-5-ones (1a-g) and 2-aryl-1,3,4-oxadiazoline-5-thiones (2a-g), respectively, in m-cresol at 150-160 deg C.Alternative routes leading to the formation of 3a and 4a are also reported.