反应详情

温度

60 °C

In a sulphonating flask which is provided with a water trap, 2.75 g (0.02 mole) of 4,5-dimethyl-2-aminophenol in 80 ml of xylene are stirred with 2.45 g (0.024 mole) of acetic anhydride for 1 hour at 60° C., and then 5.06 g (0.02 mole) of 2-(p-methoxyphenyl)-6-formyl-benzoxazole of the formula (112) and 4.35 g (0.013 mole) of toluene-4-sulphonic acid monohydrate are added to the xylene solution. The reaction mixture is stirred for 3 hours under reflux. The white suspension turns into a brown solution, in the process of which 1.9 ml of water are separated off by xylene/water azeotropic distillation. Then 70 ml of xylene are distilled off under normal pressure, the residue is cooled to 60° C. and 200 ml of methanol are added. The reaction mixture is cooled to room temperature and the precipitate is collected by filtration and washed with 60 ml of methanol, affording 5.1 g (64% of theory) of 1-[2-(6-methoxyphenyl)-benzoxazol-6-yl]-2-(5,6-dimethylbenzoxazol-2-yl)-ethylene of the formula ##STR37## as a light yellow product. Recrystallisation from a solvent mixture of 350 ml of xylene and 350 ml of nonane with the addition of fuller's earth yields 4 g of greenish yellow crystals with a melting point of 223°-224° C.

1. customIn a sulphonating flask which is provided with a water trap
2. temperatureunder reflux
3. customare separated off by xylene/water azeotropic distillation
4. distillationThen 70 ml of xylene are distilled off under normal pressure
5. addition200 ml of methanol are added
6. temperatureThe reaction mixture is cooled to room temperature
7. filtrationthe precipitate is collected by filtration
8. washwashed with 60 ml of methanol