反应详情

71 g of 5-(4-nitrophenoxy)-salicylic acid prepared in accordance with Example 1a were hydrogenated at 90° C/100 atms. in 400 ml of ethanol or methanol in the presence of 2.8 g of Raney nickel. The adsorption of hydrogen ceased after 3 hours at the longest. Following the addition of 100 ml of dimethyl acetamide, the catalyst was separated off under heat, water was added at 100° C until a haze began to form, after which the solution was heated for 20 minutes in the presence of 20 g of active carbon and the free aminophenoxy salicylic acid allowed to crystallise out after filtration, being obtained in a yield of 50 g (79% of the theoretical yield), m.p. 223° - 224° C.

1. customwere hydrogenated at 90° C
2. customthe catalyst was separated off
3. temperatureunder heat
4. additionwater was added at 100° C until a haze
5. customto form
6. temperatureafter which the solution was heated for 20 minutes in the presence of 20 g of active carbon
7. customto crystallise out
8. filtrationafter filtration
9. custombeing obtained in a yield of 50 g (79% of the
10. customtheoretical yield), m.p. 223° - 224° C.