542 results about "N-Butyrate" patented technology

The invention discloses a method for preparing butyrate clevidipine. The method comprises that 2, 3-dichlorobenzaldehyde, acetoacetate propionitrile ester and 3-amino-2-methyl crotonate are mixed and one-pot Hantzsch reaction is conducted, base catalyst is added to remove 2-cyanoethyl to obtain key intermediate, the key intermediate reacts with n-butyric acid chloromethyl ester to obtain butyrate clevidipine crude product, and the crude product is recrystallized to obtain high-purity butyrate clevidipine. Raw material 3-amino-2-methyl crotonate can be prepared by using low-price methyl acetoacetate. Raw material acetoacetate propionitrile ester can be prepared by using diketene. The synthesis of all raw materials requires no chromatographic separation for purification. The intermediate is synthesized through one-pot Hantzsch reaction, the reaction speed is fast, the condition is mild, the technological reliability is high and the purity of the intermediate is high. The conditions for the reaction of the key intermediate and the n-butyric acid chloromethyl ester can be easily controlled, the operation is simple and convenient, the cost is low, the post treatment requires no chromatographic separation for purification, the purity of the obtained butyrate clevidipine is above 99.5 percent and the mass production can be realized.