反应详情

温度

5 °C

To a solution of 3-methoxy-propionamidine hydrochloride (4.8 g, 0.035 mol) in methanol (20 mL) at 0° C. under vigorous stirring was added dropwise bromine (1.78 mL, 0.035 mol) and a 5.4M sodium methylate solution in methanol (13 mL, 0.035 mol) simultaneously over 30 min maintaining a slight bromine excess by color. To the resulting nearly colorless suspension was added dropwise a solution of potassium thiocyanate (3.37 g, 0.035 mol) in methanol (20 mL) over 10 min at 0-10° C. The resulting mixture was stirred for 2 h at 0-10° C. and then filtered. The isolated material was washed with methanol and dried which afforded a brown solid which was purified by flash chromatography (300 g silica gel 60, 5% methanol/diethyl ether) and crystallized from diethyl ether/hexanes which afforded 3-(2-methoxy-ethyl)-[1,2,4]thiadiazol-5-ylamine (4.08 g, 74%) as a light yellow solid.

1. filtrationfiltered
2. washThe isolated material was washed with methanol
3. customdried which
4. customafforded a brown solid which
5. customwas purified by flash chromatography (300 g silica gel 60, 5% methanol/diethyl ether)
6. customcrystallized from diethyl ether/hexanes which