反应详情

A mixture of sodium p-hydroxymandelate monohydrate (208 g.), sodium cyanide (49 g.), potassium carbonate (69 g.), methyl formate (80 ml.) and methanol (300 ml.) is heated under reflux for 8 hours, the temperature being maintained below 58° C. as methyl formate is consumed in the early stages of the reaction by the dropwise addition of further methyl formate (120 ml.). The mixture is cooled and acidified to pH 4 with concentrated aqueous hydrochloric acid (90 ml.), and water (300 ml.) is added dropwise whilst the mixture is distilled under reduced pressure, until the final volume of the two-layer mixture is 530 ml. The upper organic layer is collected and the lower aqueous layer is extracted twice with methyl isobutyl ketone (80 ml. each time). The extracts and organic layer are combined and the mixture is washed with saturated sodium chloride solution (100 ml.) and then with water (80 ml.). The methyl isobutyl ketone is removed by evaporation and there is thus obtained as residue p-hydroxybenzyl cyanide (120 g.) which is suitable for conversion to p-hydroxyphenylacetamide without further purification.

1. temperatureis heated
2. temperatureunder reflux for 8 hours
3. customis consumed in the early stages of the reaction by the dropwise addition of further methyl formate (120 ml.)
4. temperatureThe mixture is cooled
5. additionis added dropwise whilst the mixture
6. distillationis distilled under reduced pressure
7. customThe upper organic layer is collected
8. extractionthe lower aqueous layer is extracted twice with methyl isobutyl ketone (80 ml
9. washthe mixture is washed with saturated sodium chloride solution (100 ml.)
10. customThe methyl isobutyl ketone is removed by evaporation and there