tert-Butylharnstoff Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R37:Reizt die Atmungsorgane.
R20/21/22:Gesundheitssch?dlich beim Einatmen,Verschlucken und Berührung mit der Haut.
S-S?tze Betriebsanweisung:
S22:Staub nicht einatmen.
S24/25:Berührung mit den Augen und der Haut vermeiden.
Chemische Eigenschaften
white crystals or crystalline powder
Vorbereitung Methode
tert-Butylurea is produced by
treating 1 mol urea with 2 mol of tert-butanol in
the presence of 2 mol of concentrated sulfuric
acid at 20–25 ℃ with ice cooling.
l?uterung methode
Possible impurity is N,N'-di-tert-butyl urea which is quite insoluble in H2O. Recrystallise it from hot H2O, filter off insoluble material, and cool to 0o to -5o with stirring. Dry in vacuum at room temperature over KOH or H2SO4. If dried at higher temperatures, it sublimes slowly. It can be recrystallised from EtOH as long white needles or from 95% aqueous EtOH as plates. During melting point determination the bath temperature has to be raised rapidly as the urea sublimes slowly above 100o at 760mm. [Smith & Emerson Org Synth Coll Vol III 151 1955, Beilstein 4 IV 665.]
tert-Butylharnstoff Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
