一锅法合成4-氨基-3,5-二氯-2,6-二氟吡啶  

One-pot Synthesis of 4-Amino-3,5-dichloro-2,6-difluoropyridine

作　　者：何小强 吴承丽 HE Xiao-qiang;WU Cheng-li(Chongqing Huage Biochemistry Co., Ltd., Chongqing 404020, Chin)

机构地区：[1]重庆华歌生物化学有限公司,重庆万州404020

出　　处：《当代化工》2018年第5期935-937,共3页Contemporary Chemical Industry

摘　　要：研究了氟草烟的重要中间体4-氨基-3,5-二氯-2,6-二氟吡啶的合成新方法。以五氯吡啶为原料,采用分子筛控制水分,经氟化、氨基化一锅法合成4-氨基-3,5-二氯-2,6-二氟吡啶。最佳反应条件为:氟化反应水分含量0%~0.001%,氟化反应温度110~120℃,氨化反应温度为0~5℃,氨水浓度为20%~22%。最终4-氨基-3,5-二氯-2,6-二氟吡啶的合成收率达到83%以上,含量达到85.0%。A novel synthesis method of 4-amino-3,5-dichloro-2,6-difluoropyridine as an important intermediate of fluroxypy was researched. The 4-amino-3,5-dichloro-2,6-difluoropyridine product was synthesized from pentachloropyridine by one-pot method via molecular sieve drying, fluorination and amination. The best process condition was as follows： the moisture content 0%~0.001% and the temperature 110~120℃ in the fluorination; the temperature 0~5℃ and ammonia concentration 20%~22% in the ammoniation.The total yield and purity of the product 4-amino-3,5-dichloro-2,6-difluoropyridine were more than 83.0% and 85.0%.

关 键 词：4-氨基-3 5-二氯-2 6-二氟吡啶 五氯吡啶 分子筛 一锅法 

分 类 号：TQ460.3[化学工程—制药化工]