2,4-Dichloroquinoline-3-carbonitrile (1) reacted with several nucleophiles produced a novel substituted quinolines. Nucleophilic substitution of 1 with thiolate anions leads to the thio ethers 2a-c. Acid hydrolysis of 2a afforded the corresponding 4-quinolinones 3. The aminoquinoline 5a,b; 7a,b and pyrazoloquinoline 9 are prepared by nucleophilic substitution of 1 with amines and N2H4, respectively. Nucleophilic substitution of 1 with azide anion yielded the azidoquinoline 10, which reacted with Hj/Pd and PPh3 to give the quinoline derivatives 13a-c. Introduction The interesting biological and medicinal activities (1-4) of quinoline derivatives prompted us to exert a great effort to synthesize several quinolines. As a continuation of our work on the synthesis of a variety of quinolines and condensed quinolines (5), the present investigation describes the synthesis of novel substituted quinolines via the action of a variety of nucleophiles on 2,4dichloroquinoline-3-carbonitrile (1)(6, 7). The t-butylthiolate anion has been used to introduce a mercapto moiety into various heterocyclic systems (8-10), since it has been shown that the t-butyl group can be eliminated by miniral acids (10-11). This reaction has been used in the present investigation as a rout for the synthesis of 3-cyano-2-mercapto-4( 1 H)-quinolone (3). Results and Discussion The nucleophilic substitution reactions of 1 with thiolate anions were performed in 2-propanol, as solvent, at reflux temperature. The reaction of 1 with t-butylthiolate anion yielded the product 2a, where the nucleophilic substitution first take place at position 2. Structure of this compound Vol. 4, No. 2, 1998 Nucfeophilic Substitution of 2,4-dicholroquinoline-3-carbonitile with differenct was readily established based on the IR spectrum, Which revealed significantly an carbonyl function at 1570 cm", characteristic for 4-quinolinones (12), whereas 2-quinolinones are known to have carbonyl absorption at 1650-1670 cm' (12,13). Consequently, the structure of isomeric 2-quinolinone for compound 2a could be excluded. Acid hydrolysis of 2a with a mixture of concentrated hydrochloric acid and 1-propanol, resulted in the formation of the corresponding 2mercaptoquinolones 3. Not surprisingly, the t-butyl group in 2a was cleaved under these reaction conditions too, leading to 3. Similarly, reaction of 1 with cyclohexyl· and benzylthiolate anions yielded the corresponding quinoline derivatives 2b and 2c, respectively. Treatment of 2b with phosphoryl chloride yielded 4-chloro-2-cyclohexylthio-quinoline-3-carbonitrile (4) . As expected, reacting compound 4 with NaOH at reflux temperature, affords 4-quinolones 2b.

中文翻译：

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2,4-二氯喹啉-3-碳腈与不同亲核试剂的亲核取代。几种新型喹啉-3-碳腈衍生物的合成

2,4-Dichloroquinoline-3-carbonitrile (1) 与几种亲核试剂反应产生了一种新型的取代喹啉。1 与硫醇阴离子的亲核取代导致硫醚 2a-c。2a的酸水解得到相应的4-喹啉酮3。氨基喹啉5a，b；7a,b 和吡唑并喹啉 9 分别通过 1 与胺和 N2H4 的亲核取代来制备。1 与叠氮阴离子的亲核取代产生叠氮喹啉 10，其与 Hj/Pd 和 PPh3 反应得到喹啉衍生物 13a-c。简介 喹啉衍生物有趣的生物和药用活性 (1-4) 促使我们付出巨大努力来合成几种喹啉。作为我们合成各种喹啉和缩合喹啉的工作的延续 (5)，本研究描述了通过各种亲核试剂对 2,4-二氯喹啉-3-腈 (1)(6, 7) 的作用合成新型取代喹啉。叔丁基硫醇盐阴离子已被用于将巯基部分引入各种杂环系统 (8-10)，因为已经表明叔丁基可以被微量酸消除 (10-11)。该反应已在本研究中用作合成 3-cyano-2-mercapto-4(1H)-quinolone (3) 的途径。结果与讨论 1 与硫醇盐阴离子的亲核取代反应在回流温度下在 2-丙醇作为溶剂中进行。1 与叔丁基硫醇盐阴离子反应生成产物 2a，其中亲核取代首先发生在 2 位。4、2号、用磷酰氯处理 2b 产生 4-氯-2-环己硫基-喹啉-3-甲腈 (4)。正如预期的那样，在回流温度下使化合物 4 与 NaOH 反应，得到 4-喹诺酮类 2b。