反应详情

To a 8% aqueous solution of 0.1 mole (19.02 g.) 2,2,4-trimethyl-7-hydroxy-(2H)-chromene and 0.2 mole (8 g.) sodium hydroxide 4 g. of benzene-tributyl-ammonium-chloride as phase transfer catalyst and a solution of 0.2 mole 1,2-dibromo-ethane in 200 ml. methylene-chloride are added under stirring and the solution is heated for 12 hours. After cooling the organic layer is separated and dried above sodium sulphate and evaporated. The residue is dissolved in 50 ml. diethyl-ether and the substance is precipitated by adding 300 ml. of n-hexane. The solvent is decanted from the precipitated substance. Thus 19.38 g. (0.065 mole) product are obtained in the form of a white waxy oily substance.

1. temperaturethe solution is heated for 12 hours
2. temperatureAfter cooling the organic layer
3. customis separated
4. dry with materialdried above sodium sulphate
5. customevaporated
6. dissolutionThe residue is dissolved in 50 ml
7. customdiethyl-ether and the substance is precipitated
8. additionby adding 300 ml
9. customThe solvent is decanted from the precipitated substance