2-Nitro-3-aminopyridine is prepared by (a) reacting 3-aminopyridine with phosgen COCl.sub.2 or urea H.sub.2 NCONH.sub.2 to give N,N'-di-(3-pyridyl)-urea, (b) nitrating and N,N'-di-(3-pyridyl)-urea with nitric acid or with a mixture of nitric acid and sulfuric acid to give N,N'-di-(2-nitor-3-pyridyl)-urea, and (c) hydrolyzing said N,N'-di-(2-nitro-3-pyridyl)-urea to give 2-nitro-3-amino-pyridine. N,N'-di-(3-pyridyl)-urea and N,N'-di-(2-nitro-3-pyridyl)-urea, which are formed in the course of the reaction as intermediates are new compounds. The end product of the process, 2-nitro-3-aminonpyridine, is an intermediate in various specialized fields.
2-硝基-3-
氨基吡啶的制备方法为:(a)将3-
氨基吡啶与
光气COCl.sub.2或
尿素H.sub.2NCONH.sub.2反应,得到N,N'-二-(3-
吡啶基)-
尿素,(b)将N,N'-二-(3-
吡啶基)-
尿素与
硝酸或
硝酸和
硫酸混合液硝化,得到N,N'-二-(2-硝基-3-
吡啶基)-
尿素,(c)
水解所述的N,N'-二-(2-硝基-3-
吡啶基)-
尿素,得到2-硝基-3-
氨基吡啶。在反应过程中形成的中间体N,N'-二-(3-
吡啶基)-
尿素和N,N'-二-(2-硝基-3-
吡啶基)-
尿素是新化合物。该过程的终产物2-硝基-3-
氨基吡啶是各种专业领域中的中间体。