Preparation method of salazosulfapyridine

The invention provides a preparation method of salazosulfapyridine. The preparation method comprises the following steps: S1, carrying out a cyclic condensation reaction on sulfaguanidine serving as astarting raw material and a C3 active compound to obtain sulfadiazine; S2, dissolving the sulfadiazine obtained in the step S1 in an aqueous solution containing sodium nitrite for a diazotization reaction so as to further obtain a diazonium salt; and S3, transferring the diazonium salt obtained in the step S2 into an aqueous sodium hydroxide solution, and carrying out a coupling reaction with salicylic acid to finally obtain salazosulfapyridine. Aiming at the defects in the prior art, the invention provides the preparation method of salazosulfapyridine; and according to the preparation method, raw materials are easy to obtain, and the purity and yield of the obtained purified product are high. 本发明提供了一种柳氮磺吡啶的制备方法，包括以下步骤：S1：以磺胺脒为起始原料，与三碳活性化合物进行环状缩合反应获取磺胺嘧啶；S2：将步骤S1中的磺胺嘧啶溶解在含有亚硝酸钠的水溶液中进行重氮化反应，进一步获取重氮盐；S3：将步骤S2中获取的重氮