Preparation method of 6-amino-1,3-dimethyluracil

Abstract

The invention discloses a preparation method of 6-amino-1,3-dimethyluracil. According to the preparation method, cyanoacetic acid and 1,3-dimethylurea undergo condensation under the action of acetic anhydride so as to obtain 2-cyano-N-methyl-N-[(methylamino)carbonyl]acetamide; and then 2-cyano-N-methyl-N-[(methylamino)carbonyl]acetamide undergoes a cyclization reaction under an alkaline conditionso as to obtain 6-amino-1,3-dimethyluracil. The 6-amino-1,3-dimethyluracil has a good system stabilizing effect when used as a main component of a PVC stabilizer along with zinc stearate, and has a better synergistic effect than a commonly-used counterpart in the industry at present. The 6-amino-1,3-dimethyluracil can absorb HCl and also can replace unstable chlorine atoms. On the other hand, the6-amino-1,3-dimethyluracil also can react with ZnCl2 to generate a metal complex and inactivate ZnCl2. Thus, long-term stability of a PVC sample is greatly enhanced.

Description

technical field

[0001] The invention relates to the technical field of chemical engineering, in particular to a preparation method of 6-amino-1,3-dimethyluracil. Background technique

[0002] Due to the poor thermal stability of polyvinyl chloride, corresponding stabilizers must be added to repair the defects of the PVC chain, and at the same time absorb the HCL produced by PVC dechlorination in time. To achieve good stability of polyvinyl chloride, it is often necessary to use multiple PVC heat stabilizers at the same time.

[0003] Defects and deficiencies in the prior art: the lead salt composite stabilizer has good thermal stability and has been widely used, but the lead salt has double hazards to the human body and the environment. The development and research of PVC stabilizers tend to be non-toxic and pollution-free. Cd, Research on the development of alternatives to Pb stabilizers is very active.

[0004] Calcium stearate and zinc stearate are cheap, non-toxic heat...