Preparation method of pyridine-3-sulfonyl chloride

The invention belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of pyridine-3-sulfonyl chloride. The method comprises the following steps: S1, adding concentrated hydrochloric acid into a reaction container, controlling the temperature to be 20 DEG C or below, adding 3-aminopyridine into the concentrated hydrochloric acid, stirring, dissolving, controlling the temperature to be-15 DEG C to-5 DEG C, and dropwise adding a sodium nitrite solution to prepare a diazonium salt solution for later use; and S2, in another reaction container, adding the diazonium salt solution obtained in the step S1 into a dichloromethane solution of sodium hydrogen sulfite and cuprous chloride at a controlled temperature of-20 to-10 DEG C, carrying out heat preservation and stirring reaction after the diazonium salt solution is added, then carrying out liquid separation, extracting a water layer once by using dichloromethane, and carrying out vacuum concentration on an organic laye