反应 #1244317

反应方程式

Carbon disulfide

Benzo[1,3]dioxole-5-carboxylic acid hydrazide

potassium hydroxide

methanol

carbon disulfide

→

5-Benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazole-2-thiol

溶剂

Water

反应条件

后处理

1. 1
   workup.STIRRINGThe mixture was stirred
2. 2
   温度at reflux for 20 hours
3. 3
   温度reflux for 4 h
4. 4
   其他the excess of carbon disulfide and methanol was evaporated
5. 5
   workup.ADDITIONby adding concentrated hydrochloric acid to pH 3-4
6. 6
   其他The product precipitated
7. 7
   过滤filtered
8. 8
   洗涤was washed with water (50 ml)

实验过程

Benzo[1,3]dioxole-5-carboxylic acid hydrazide (45.8 g, 254 mmol) was added to a mixture of potassium hydroxide (15.7 g, 280 mmol) and methanol (350 ml). The mixture was stirred for 30 minutes at room temperature. Carbon disulfide (38.7 g, 508 mmol) was added. The mixture was stirred at reflux for 20 hours, followed by another portion of carbon disulfide (12.7 g, 167 mmol) and reflux for 4 h. Water (300 ml) was added and the excess of carbon disulfide and methanol was evaporated. The aqueous suspension was acidified by adding concentrated hydrochloric acid to pH 3-4. The product precipitated, filtered and was washed with water (50 ml). Yield 53.5 g (95%) as yellow powder.

来源