Reaktion #56275

Reaktionsgleichung

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

benzoyl isocyanate

urea

→

residue

Ausbeute 35.5%

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

Ausbeute 35.5%

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONA magnetic stirring bar was added
2. 2
   Sonstigethe vessel sealed
3. 3
   SonstigeThe stirred reaction mixture
4. 4
   Sonstigeprecipitates
5. 5
   SonstigeThe urea was removed by filtration
6. 6
   Einengenthe filtrate concentrated in vacuo

Vorschrift

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.

Quelle