反应详情

温度

85 °C

A 1,000 milliliter, 3-neck flask equipped with a Claisen adaptor, paddle stirrer, thermometer, addition funnel and condenser, was charged with 100 grams (0.602 moles) of 2-phenoxypropanoic acid, (54.8 grams, 0.602 mole) of thiosemicarbazide and 300 ml. of dioxane. The slurry was heated to 85° C. and the addition funnel was charged with phosphorous oxychloride (POCl3). The POCl3 was slowly added (for 70 minutes) while maintaining the temperature within 90°-95° C., and then stirred for an additional 20 minutes. It was refluxed for 105 minutes and cooled. The flask was evacuated by using a water aspirator to remove volatiles (HCl, POCl3 and some dioxane), leaving a viscous residue to which 400 ml of water was added and the residue emulsified. A 50 percent solution of NaOH was added until the pH of the solution was 10, and a solid precipitate formed. The solid precipitate was filtered off, washed with water, air dried, then dried in a vacuum oven at 60° C. to a granular grey solid which was recrystallized from H2O/ethanol mixture, filtered and then dried in a vacuum oven at 60° C. to white needles of 5-(1-phenoxyethyl)-2-amino- 1,3,4-thiadiazole. (Melting point 157°-167° C.).

1. customA 1,000 milliliter, 3-neck flask equipped with a Claisen adaptor, paddle stirrer
2. additionthermometer, addition funnel and condenser
3. temperaturewhile maintaining the temperature within 90°-95° C.
4. temperatureIt was refluxed for 105 minutes
5. temperaturecooled
6. customThe flask was evacuated
7. customto remove volatiles (HCl, POCl3
8. customsome dioxane), leaving a viscous residue to which 400 ml of water
9. additionwas added
10. customa solid precipitate formed
11. filtrationThe solid precipitate was filtered off
12. washwashed with water, air
13. customdried
14. customdried in a vacuum oven at 60° C. to a granular grey solid which
15. customwas recrystallized from H2O/ethanol mixture
16. filtrationfiltered
17. dry with materialdried in a vacuum oven at 60° C. to white needles of 5-(1-phenoxyethyl)-2-amino- 1,3,4-thiadiazole