以丙酮氰醇为氰源高效制备β-氰基酮

Efficient synthesis of β-cyano ketones using acetone cyanohydrin as cyanogen source

摘要:

β-氰基酮是重要的精细化工中间体，其中的氰基可以转化为酰胺、胺、羧酸及其衍生物、醛、酮、醇、含氮杂环等。以廉价低毒的丙酮氰醇为氰源，通过α,β-不饱和羰基化合物的共轭氰化反应，实现了β-氰基酮的高效制备。考察了碱的种类及用量、温度、溶剂、丙酮氰醇用量等因素对反应的影响。结果表明，最优实验条件为：采用LiOH·H2O作碱，反应底物、丙酮氰醇、LiOH·H2O的物质的量比为1:2.5:1.6，以V(DMF)∶V(H2O)=4∶1为溶剂，反应温度为60℃。在最优条件下，β-氰基酮的最高收率为98%。进一步考察底物适用范围表明，16种查尔酮衍生物均能以85%?98%的收率得到相应的β-氰基酮。

Abstract:

β-cyano ketones are important fine chemical intermediates, in which cyano groups can be converted into amides, amines, carboxylic acids and their derivatives, aldehydes, ketones, alcohols, nitrogen-containing heterocycles, etc. Using cheap and low-toxic acetone cyanohydrin as the cyanogen source, the efficient preparation of β-cyano ketone was achieved through the conjugate cyanation reaction of α,β-unsaturated carbonyl compounds. The influence factors such as the type and amount of base, temperature, solvent, and the amount of acetone cyanohydrin on the reaction were investigated. Results showed that the optimal experimental conditions were obtained as follows: LiOH·H2O was used as the base, the amount of substance ratio of reaction substrate, acetone cyanohydrin, and LiOH·H2O was 1:2.5:1.6, DMF and H2O in a volume ratio of 4:1 was used as solvent, and the reaction temperature was 60 °C. Under the optimal conditions, the highest yield of β-cyano ketone was 98%. Further investigation of the scope of substrates showed that the corresponding β-cyano ketones could be obtained from 16 chalcone derivatives in the yield of 85%~98%.