7-(3,4-二氰基苯氧基)-4-甲基香豆素的合成

Synthesis of 7-( 3,4-Dicyanophenoxy)-4-methylcoumarins

以间苯二酚和乙酰乙酸乙酯为原料,在浓硫酸的催化下合成7-羟基-4-甲基香豆素。以4-硝基邻苯二甲酰亚胺为原料,通过氨水催化开环,三氯氧磷脱水制得4-硝基邻苯二甲腈。得到的7-羟基-4-甲基香豆素和4-硝基邻苯二甲腈经过亲核取代反应得到7-(3,4-二氰基苯氧基)-4-甲基香豆素。考察了7-羟基-4-甲基香豆素和4-硝基邻苯二甲腈的投料比、缚酸剂用量、反应温度和反应时间对反应的影响,最优反应条件为:n(7-羟基-4-甲基香豆素)∶n(4-硝基邻苯二甲腈)∶n(无水碳酸钾)=1.4∶1.0∶1.5,反应温度30℃,反应时间14 h,收率为63.7%,并通过红外吸收光谱、核磁共振氢谱和高效液相色谱(色谱纯度为99.30%)对合成的化合物的结构进行了确证。在该条件下适当放大实验条件得到收率基本在83.1%,比文献报道收率68%要高。

7-Hydroxy-4-methylcoumarin was synthesized from resorcinol and ethyl acetoacetate under the catalysis of concentrated sulfuric acid. 4-Nitro-phthalimide as raw material was first in the open-loop catalytic ammonia and then went through dehydration with phosphorus oxychloride to get 4-nitro- phthalonitrile. The two obtained compounds then went through nucleophilic substitution reaction to form 7-（ 3,4-dicyanophenoxy）-4-methylcoumarin. By investigating the feed ratio, the amount of acid binding agent, the reaction temperature and reaction time, we confirmed the optimal reaction conditions to be as follows： the molar ratio between 7-hydroxy-4-methylcoumarin, 4-nitro-phthalonitrile and anhydrous potassium carbonate was 1.4 ： 1.0： 1.5, the temperature was 30 ℃, and the reaction time was 14 h ; under such conditions the yield was 63.7%. And the structures of the synthesized compounds have been confirmed by IR, 1HNMR and high performance liquid chromatography （purity 99.30 % ）. By scaling up the experimental conditions, we get the yield of about 83.1%, which is higher than the reported yield of 68%.