Reacción #1144441

Ecuación de reacción

NaOH

p-toluenesulfonic acid

2-amino-4-tert-amyl-phenol

p-nitrobenzoyl chloride

HCl

HCl

2-tert-butylamino-4,6-dichloro-1,3,5-triazine

→

2-(4-nitrophenyl)-6-tert-amyl-benzoxazole

Disolventes

xylene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe whole is heated
2. 2
   Temperaturaunder reflux for 4 hours
3. 3
   TemperaturaAfter cooling at 30° C.
4. 4
   Lavadothe precipitate is washed twice with xylene and three times with acetone
5. 5
   Otrodried in a static dryer

Procedimiento

B)—185 Grams of melted p-nitrobenzoyl chloride (80-85° C.) are dropped into a round-bottom flask containing 179 g of 2-amino-4-tert-amyl-phenol in 1000 m of xylene. The resulting suspension is heated slowly to 130° C., neutralizing the formed HCl with aqueous NaOH. When evolution of HCl is over, the reaction mixture is added with 9.5 of p-toluenesulfonic acid, and the whole is heated under reflux for 4 hours. After cooling at 30° C., the precipitate is washed twice with xylene and three times with acetone, then dried in a static dryer, thereby obtaining 228 g of 2-(4-nitrophenyl)-6-tert-amyl-benzoxazole (M.p. 147-48° C.). This product is placed in autoclave containing 1100 ml of ethylene glycol monomethyl ether and 3 g of Pt/C. After washing the reaction medium first with nitrogen and then with hydrogen, the hydrogen pressure is brought to 10 atm, heating to 80-90° C., and these conditions are kept until ceasing of hydrogen adsorption by the system. After cooling and depressurising, the mixture is washed with nitrogen, the catalyst is filtered off and the resulting solution is dried under vacuum. The resulting residue is crystallized from xylene. Yield: 232 g of 2-(4-aminophenyl)-5-tert-amyl-benzoxazole. M.p.: 152-54° C.

Fuente