反応 #56275

反応方程式

1-methyl-3-(3-trichloromethyl-1,2,4-thiadiazol-5-yl)urea

benzoyl isocyanate

urea

→

residue

収率 35.5%

1-Benzoyl-3-methyl-5-(3-trichloromethyl-1,2,4-thiadiazol-5-yl)biuret

収率 35.5%

溶媒

benzene

反応条件

後処理

1. 1
   workup.ADDITIONA magnetic stirring bar was added
2. 2
   その他the vessel sealed
3. 3
   その他The stirred reaction mixture
4. 4
   その他precipitates
5. 5
   その他The urea was removed by filtration
6. 6
   濃縮the filtrate concentrated in vacuo

実験手順

A glass pressure vessel was charged with 5.5 grams (0.02 mole) 1-methyl-3-(3-trichloromethyl-1,2,4-thiadiazol-5-yl)urea, 3.2 grams (0.02 mole) benzoyl isocyanate and 50 milliliters benzene. A magnetic stirring bar was added and the vessel sealed. The stirred reaction mixture was heated at 145° C. for 1.5 hours and then allowed to cool to room temperature where 4.5 grams of starting urea precipitates. The urea was removed by filtration and the filtrate concentrated in vacuo to leave 3.0 grams of residue. Extraction of the residue with hot cyclohexane, followed by cooling the extract yielded 0.2 grams (11% selectivity) of pure product; m.p. 70° C.

出典