反应详情

17.5 g of 6-acetoxy-2-(4-aminophenoxymethyl)-2,5,7,8-tetramethylchroman (prepared as described in Preparation 50) were dissolved in a mixture of 130 ml of acetone and 30 ml of water. 13 ml of concentrated hydrochloric acid, and then 8.5 ml of water containing 4.3 g of sodium nitrite, was added dropwise to this solution in an ice bath. A further 37.3 ml of ethyl acrylate were then added dropwise, and then the reaction mixture was heated to 40°-43° C.; at this temperature, 680 mg of cuprous oxide were added slowly. After about 30 minutes, nitrogen generation finished. The reaction mixture, which had separated into two layers, was mixed with benzene to extract the organic layer. The benzene extract was washed with a saturated aqueous solution of sodium chloride and then dried over anhydrous sodium sulfate. The solvent was distilled off and the resulting dark brown oil was subjected to silica gel column chromatography. After the first elution with a 1:1 by volume mixture of benzene and cyclohexane, the title compound was obtained from the next elution with a 2:1 by volume mixture of benzene and cyclohexane and from the subsequent elution with benzene alone.

1. temperaturethe reaction mixture was heated to 40°-43° C.
2. customThe reaction mixture, which had separated into two layers
3. additionwas mixed with benzene
4. extractionto extract the organic layer
5. extractionThe benzene extract
6. washwas washed with a saturated aqueous solution of sodium chloride
7. dry with materialdried over anhydrous sodium sulfate
8. distillationThe solvent was distilled off
9. washAfter the first elution with a 1:1
10. additionby volume mixture of benzene and cyclohexane