Palladium-catalyzed Carbonylation Of O-aminobenzoic Acids With Primary Amines To Quinazoline-2,4(1H,3H)-diones

Quinazoline-2,4(1H,3H)-dione derivatives are nitrogen-containing heterocyclic compounds with a wide range of pharmaceutical activities and biological activities,which are widely used in medicine,pesticides and organic synthesis.Therefore,the synthesis of quinazoline-2,4(1H,3H)-dione derivatives is currently a hot research direction.Up to now,there have been many mature methods for synthesizing quinazoline-2,4(1H,3H)-dione derivatives,but these methods still have many shortcomings need to be improved,such as high toxicity of raw materials,complex structure of raw materials,complex catalytic system and low atom economy.In this paper,a new approach has been developed: quinazoline-2,4(1H,3H)-dione derivatives can be obtained from simple,cheap and easily available o-aminobenzoic acid and primary amine;using copper acetate as oxidant,palladium acetate as catalyst and CO as carbonylation reagent.Therefore,a new way has been opened up for the synthesis of such compounds with easily available raw materials,mild reaction conditions,high atom economy and short synthesis route?This article is divided into three chapters,briefly summarized as following:Chapter 1.Literature review.There are four parts in this chapter:(1)The usage of quinazoline-2,4(1H,3H)-diones;(2)Main synthetic methods of quinazoline-2,4(1H,3H)-diones;(3)Brief introduction of palladium acetate-catalyzed carbonylation reactions with CO;(4)The topic selection and conception of this dissertation.Chapter 2.Palladium-catalyzed carbonylation of o-aminobenzoic acid with primary amine to quinazoline-2,4(1H,3H)-diones.In this chapter,palladium-catalyzed carbonylation of anthranilic acid to quinazoline-2,4(1H,3H)-dione derivatives was studied.Firstly,the reaction conditions such as additives,addition modes of reagents,oxidants,reaction temperature,catalysts,solvents and reaction time were optimized and screened.Then,the applicability of different substrates to this reaction system was explored on the basis of the optimized conditions,and a series of quinazoline-2,4(1H,3H)-diones were synthesized.Chapter 3.Mechanism discussion.The possible reaction mechanism of palladium-catalyzed carbonylation of anthranilic acid to quinazoline-2,4(1H,3H)-dione derivatives was discussed on the basis of literature investigation and the control experiments.