反应详情

温度

50 °C

Anhydrous hexamethylphosphotriamide (5 cc) and 4-carboxy-5-(pyrazin-2-yl)-1,2-dithiole-3-thione (1.28 g) (prepared as described in Example 32) are added to a solution of dry sodium ethoxide (0.34 g) in anhydrous ethanol (5 cc). The suspension obtained is heated to a temperature of about 50° C., the resulting solution is cooled to a temperature of about 20° C. and then butyl iodide (1.7 g) is added. The reaction mixture is then maintained at a temperature of about 50° C. for 7 hours. An insoluble material is filtered off and the filtrate is evaporated to dryness under reduced pressure (20 mm Hg). The oil obtained is treated with ethyl acetate (2 cc) and the product which crystallises is filtered off and washed with diethyl ether (2 cc). After drying, 4-butoxycarbonyl-5-(pyrazin-2-yl)-1,2-dithiole-3-thione (0.4 g), melting at 127° C., is obtained.

1. customThe suspension obtained
2. temperaturethe resulting solution is cooled to a temperature of about 20° C.
3. temperatureThe reaction mixture is then maintained at a temperature of about 50° C. for 7 hours
4. filtrationAn insoluble material is filtered off
5. customthe filtrate is evaporated to dryness under reduced pressure (20 mm Hg)
6. customThe oil obtained
7. customthe product which crystallises
8. filtrationis filtered off
9. washwashed with diethyl ether (2 cc)
10. customAfter drying