反应详情

温度

0 °C

5-Amino-2-methyl-1H-benzimidazol hydrochloride (16.51 g) was dissolved in concentrated hydrochloric acid (200 ml), and this was cooled to 0° C. An aqueous solution (15 ml) of sodium nitrite (7.59 g) was added dropwise thereto at 0° C. over 20 minutes. This was stirred for 20 minutes. Then, a concentrated hydrochloric acid solution (20 ml) of tin (II) chloride dihydrate (55.7 g) was added dropwise thereto at 0° C. over one hour, and then this was stirred for 30 minutes. The precipitated solid was collected by filtration, and washed with water, and dried. Thus, crude (2-methyl-1H-benzimidazol-5-yl)-hydrazine dihydrochlide was obtained.

1. waitat 0° C. over one hour
2. stirringthis was stirred for 30 minutes
3. filtrationThe precipitated solid was collected by filtration
4. washwashed with water
5. customdried