One-pot Synthesis of 5-Unsubstituted 3,4-Dihydropyrimidin-2(1H)-ones from Aldehydes,Ketones, and Urea under Solvent-free Conditions

Various 5-unsubstituted 3,4-dihydropyrimidin-2(1H)-ones were synthesized efficiently by a one-pot three-component condensation of aromatic aldehydes, aromatic ketones, and urea using SnCl₂·2H₂O as a catalyst under solvent-free conditions. All products were identified by IR, NMR, MS, and elemental analysis. The novel method offers several advantages such as excellent yields (81–95%), short reaction time (5–16 min), broader substrate scope, and environmentally friendly conditions.     

无溶剂微波辅助一锅法合成吡喃并[2,3-c]吡唑衍生物

绿色、高效、简便的催化多组分一锅法反应符合当前所倡导的"绿色"化学理念,是当今有机化学的研究热点.通过在无溶剂微波辅助条件下,使用廉价易得的KF/A1203催化吡唑啉酮、芳香醛和丙二腈的多组分"一锅法"反应,合成了一系列吡喃并[2,3-c]吡唑衍生物,反应时间为5-10 min,产率为85％-98％.标题化合物的结构经...     

HBF4-catalyzed Biginelli reaction: One-pot synthesis of dihydropyrimidin-2(1H)-ones under solvent-free conditions

An efficient synthesis of dihydropyrimidinones from the aldehyde, 1,3-dicarbonyl compound and urea (thiourea) under solvent-free conditions, using fluoroboric acid as the catalyst, is described. Compared with the classical Biginelli reaction conditions, this new protocol has the advantage of high yields, short reaction time and simplicity in the experimental procedure.     

Chloroferrate(III) Ionic Liquid: Efficient and Recyclable Catalyst for Solvent-free Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones

A water-tolerant Lewis acidic ionic liquid, [bmim][FeCl₄], was found to be an efficient and recyclable catalyst in the synthesis of 4-aryl-dihydropyrimidinones through Biginelli condensation. This method is capable of being scaled up, if desired.     

无溶剂无催化剂条件下合成betti碱

在无溶剂无催化剂条件下,无论是含有吸电子基团还是含有供电子基团的芳香醛都能与2-萘酚以及仲胺反应,短时间内以高产率生成氨基烷基萘酚。该方法实验操作简单,不需要使用催化剂和溶剂,减少了废物排放,降低了成本,是一种绿色合成氨基烷基萘酚的方法。     

n-Bu2SnO催化一锅法合成3,4-二氢嘧啶-2-酮

采用n-Bu2SnO作催化剂,醛、β-酮酸酯和脲在无溶剂条件下于100℃发生Bigineui缩合反应。合成了19个3,4-二氢嘧啶-2-酮衍生物,反应时间短,产率高,操作简便,且催化剂可以重复使用多次。     

一锅法合成2,3-二氯吡啶

2,3-二氯吡啶是新型杀虫剂氯虫苯甲酰胺的关键中间体。比较了2,3-二氯吡啶的各种合成方法,探索了一条以3-氨基吡啶为原料,经过氯化、重氮化和sandmeyer反应,中间体不分离,一锅法合成2,3-二氯吡啶的经济合理的路线,收率66.9%,含量98%以上。对反应的机理进行了探讨,对副产物进行了分离与表征。     

微波无溶剂法合成双酚F

对甲基苯酚和苯酚混合,加入催化剂,混合研磨.在无溶剂微波辐照下,成功地合成了双酚F.完成了产物分析鉴定,优化了反应条件,使双酚F产率达到39%.     

丙烯酸法合成5,7-二氯-4-氧代-2,3-二氢喹啉

5,7-二氯-4-氧代-2,3-二氢喹啉是合成4,5,7-三氯喹啉的重要中间物质,介绍了以丙烯酸和3,5-二氯苯胺为原料合成5,7-二氧-4-氧代-2,3-二氢喹啉,以水为溶剂,室温下搅拌混合物得到加成产物3-（3,5-二氯苯胺）丙酸,经过成环后得到5,7-二氯-4-氧代-2,3-二氢喹啉,产品收率达到85％。     

2-烷氨基-3-对氟苯基-5-甲基-6-(1H-1,2,4-三唑-1-基)-噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物的合成及其杀菌活性

已见含氟类有机物具有杀菌能力的报道,将氟元素引入到噻吩并嘧啶酮的衍生物之中,考查其杀菌活性。通过Gewald反应生成噻吩,产物同PPh3、C2Cl6、Et3N作用得到膦亚胺,再用对氟苯基异氰酸酯与之作用得到碳二亚胺,之后与伯胺反应得到10种新的标题化合物,其结构经1HNMR、MS和元素分析表征。生物活性测试表明,此类衍生物对常见农作物部分菌体均表现出较大的抑制作用,其中以2-正庚氨基-3-对氟苯基-5-甲基-6-(1H-1,2,4-三唑-1-基)-噻吩并[2,3-d]嘧啶-4(3H)-酮活性最好,它对棉花枯萎菌的抑制率达90%。该系列物质相对不含氟元素的同种取代基的噻吩并嘧啶酮衍生物的杀菌活性有一定程度的提高。     

Nucleophilic Chlorination of 3-Formyl-4-hydroxy-quinolin-2(1H)-ones

Chlorination of 1-substituted 3-formyl-4-hydroxy-2-quinolones ( 1a , b ) with phosphorylchloride leads to 4-chloro-3-dichloromethylquinolones ( 2 ), which can be hydrolyzed to 4-chloro-3-formyl-quinolones ( 4 ). From the anilinomethylene quinolinediones ( 3 ), at low temperatures the formylquinolones 4 can be obtained directly, whereas at high temperatures cleavage of the tautomeric azomethine moiety followed by subsequent ring closure to the naphthyridines ( 7 ) takes place. With 1-unsubstituted 3-formyl-4-hydroxy-2-quinolones ( 1d ) either the 3-dichloromethylquinolone ( 2d ) or the 2,4-dichloro-3-dichloro-methylquinoline ( 10 ) is obtained depending on the reaction conditions. Similar results are obtained with the 1-unsubstituted anilinomethylene compounds ( 3 ). Attempts to obtain the 3-formyl-2,4-dichloroquinoline ( 11 ) were unsuccessful because in all experiments the 2-chloro-group was converted to an oxygen function.     

两相法催化合成3,4-二氢嘧啶-2-酮

应用反应的放热原理,提出了一种建立在水的基础上的两相法合成标题化合物的新途径。在此两相反应过程中,用氨基磺酸作催化剂,醛、脲和α,β-二酮3组分为反应物,缩合制备了3,4-二氢嘧啶-2-酮,考察了不同反应物物质的量比对收率的影响。利用这种反应方法,在苯甲醛、尿素和乙酰乙酸乙酯的物质的量比为1∶1.2∶2时,3,4-二氢嘧啶-2-酮收率达到最大93%。此过程反应条件温和,操作简单,节约能源。     

一锅法合成对苯撑二（4-氨基苯并恶唑）

用对苯二甲酸、2,4-二氨基苯酚盐酸盐为原料,五氧化二磷和磷酸反应生成的多聚磷酸为催化剂,合成了对苯撑二（4-氨基苯并恶唑）。考察了催化剂配比、原料配比及粗品精制溶剂等因素对产品纯度及收率的影响。结果表明,对苯二甲酸：2,4-二氨基苯酚盐酸盐=1：2．05;磷酸：五氧化二磷=1：1．35;采用混合溶剂进行精制,在此条件下产品的最终纯度达到99．2％