Abstract: The present disclosure discloses a flamed-based vacuum generator, including a shell and a combustion assembly, where the shell has a cavity, the cavity being a space having at least one opening, and the combustion assembly includes a combustible object and an igniter, the igniter being configured to ignite the combustible object, the combustible object generating a flame in the cavity, and the flame extinguishing in the cavity. In the present disclosure, through in-depth study of the internal mechanism of vacuum generated by flame combustion, it is found that the extinguishing process of a flame is the key to the generation of vacuum, and a larger flame and more sufficient combustion indicate a higher vacuum pressure generated in the cavity after the flame is extinguished.

Abstract: The present disclosure provides a purification method for 3-amino-5-methylpiperidine with amino protected by Boc. The method includes adding a solvent to the crude product of 3-amino-5-methylpiperidine with amino protected by Boc, heating until it is dissolved to obtain a mixed solution; adding an acid and an amine crystallization auxiliary to the mixed solution, stirring and dispersing to obtain a dispersed solution; cooling the dispersed solution until crystallization, separating and drying same to obtain a salt crystal of 3-amino-5-methylpiperidine with amino protected by Boc. The present disclosure improves the product characters of 3-amino-5-methylpiperidine with amino protected by Boc after salifying and crystallization, thereby improving the yield and purity of the product, at the same time, it simplifies the operation steps of salifying and crystallization of 3-amino-5-methylpiperidine with amino protected by Boc, shortens the operation time, and reduces production costs.

Abstract: The present disclosure discloses a flamed-based vacuum generator, including a shell and a combustion assembly, where the shell has a cavity, the cavity being a space having at least one opening, and the combustion assembly includes a combustible object and an igniter, the igniter being configured to ignite the combustible object, the combustible object generating a flame in the cavity, and the flame extinguishing in the cavity. In the present disclosure, through in-depth study of the internal mechanism of vacuum generated by flame combustion, it is found that the extinguishing process of a flame is the key to the generation of vacuum, and a larger flame and more sufficient combustion indicate a higher vacuum pressure generated in the cavity after the flame is extinguished.