Efficient preparation of 3-substituted quinazolinediones directly from anthranilic acids and isocyanates
作者:Natalie Koay、Louis-Charles Campeau
DOI:10.1002/jhet.551
日期:2011.3
An efficient and practical synthesis of 3‐substituted quinazolinediones is described. The protocol uses readily available isocyanates and anthranilic acids as precursors in a one‐pot operation and has been demonstrated on >50 g scale. Isolation of the products via filtration directly from the reaction media is facile, affording high‐purity material. This procedure was then applied to the synthesis
The chemistry of azides derived from N-substituted phthalamic and tetrahalogenophthalamic acids
作者:Ting Keung Au、Ahmet E. Baydar、Gerhard V. Boyd
DOI:10.1039/p19810002884
日期:——
o-carbamoylbenzoyl azides (2), which yielded o-carbamoylphenyl isocyanates (4) when heated. The isocyanates derivedfrom tertiary phthalamic acids formed 4-dialkyl ammonio-1,4-dihydro-2H-3,1-benzoxazin-2-one perchlorates (8) by the action of perchloric acid and acetic anhydride; those containing secondary amide groups cyclised to 3-alkyl-quinazoline-2,4-(1H,3H)-diones (11) at rates depending on the size of the
用叠氮化钠处理八种高氯酸邻苯二甲亚氨酸钠,得到N-取代的邻氨基甲酰基苯甲酰基叠氮化物(2),加热时得到邻氨基甲酰基苯基异氰酸酯(4)。衍生自叔邻苯二甲酸的异氰酸酯在高氯酸和乙酸酐的作用下形成4-二烷基铵-1,4-二氢-2 H -3,1-苯并恶嗪-2-一高氯酸盐(8)。那些含有仲酰胺基的化合物以取决于烷基基团大小的速率环化成3-烷基-喹唑啉-2,4-(1 H,3 H)-二酮(11)。四氯和四溴邻苯二甲酸酐与胺反应生成相应的酰胺酸,其盐或N-取代的3-氨基-4-羟基邻苯二甲酸酯。在衍生自两种叔四氯邻苯二甲酸的叠氮化物的情况下,也观察到环链异构现象。
Traceless synthesis of quinazoline-2,4-diones by curtius rearrangement reaction using poly(ethylene glycol) as soluble polymeric support
作者:Yanling Huang、Cuifen Lu、Zuxing Chen、Guichun Yang
DOI:10.1002/jhet.5570440628
日期:2007.11
We have developed an efficient method to synthesize various quinazoline-2,4-diones using poly-(ethyleneglycol) as soluble polymeric support. The procedure of this reaction included: formation of acyl azide, efficient Curtius rearrangement, nucleophlic addition with amines to produce ureas, cyclization and concurrent cleavage of the resulted six-membered heterocycle from PEG-support in excellent yields