Preparation method of n-butylamine propyl trimethoxy silane

The invention discloses a preparation method of n-butylamine propyl trimethoxy silane, wherein the preparation method comprises the following steps: (1) putting n-butylamine and chloropropyl trimethoxy silane into a reaction kettle, beginning to a temperature-rising reaction under stirring, and controlling the reaction pressure to be 0.5 MPa-2 MPa and the reaction temperature to be 75-120 DEG C; (2) after the reaction of the step (1) is finished, controlling the temperature in the reaction kettle to be 40-50 DEG C, then adding sodium methoxide to the reaction liquid, and continuing a stirring reaction; after the reaction is finished, carrying out solid-liquid separation on the reaction liquid, and separating out a filtrate and a sodium chloride precipitate; and (3) carrying out reduced pressure distillation on the filtrate separated out in the step (2), and separating unreacted n-butylamine, generated alcohol and the required product n-butylamine propyl trimethoxy silane, to obtain the high-purity product n-butylamine propyl trimethoxy silane. The whole preparation method is simple in process, production costs can be greatly reduced, and more than 84% of the molar yield can be obtained.