反应详情

温度

5 °C

To a solution of (-)1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (5.0 g., 0.028 M) and sodium hydroxide (1.12 g., 0.028 M) in water (100 ml.) at 10° C. was slowly added (-)3-benzoylthio-2-methylpropionyl chloride (6.82 g., 0.028 M). At the same time, from a separate dropping funnel, was added a solution of sodium hydroxide (1.12 g., 0.028 M) in water (20 ml.), at such a rate that the solution was maintained at a pH between 9.5 and 7.5 pH units (final pH 7.5). After stirring overnight at 5° C., the reaction mixture was filtered and the clear filtrate acidified with dilute hydrochloric acid. The product was extracted into methylene dichloride, washed and dried over sodium sulfate. After filtration the solvent was removed by evaporation at reduced pressure, leaving a residue (8 g.). To a solution containing 0.5 g of this material in methylene dichloride was added piperazine (0.058 g., 0.67 mM). The solvent was removed and the product recrystallized from acetonitrile, giving a white solid, the title compound, as a hemipiperazine salt, m.p. 154°-155° C.

1. customat 10° C.
2. temperatureat such a rate that the solution was maintained at a pH between 9.5 and 7.5 pH units (final pH 7.5)
3. filtrationthe reaction mixture was filtered
4. extractionThe product was extracted into methylene dichloride
5. washwashed
6. dry with materialdried over sodium sulfate
7. filtrationAfter filtration the solvent
8. customwas removed by evaporation at reduced pressure
9. customleaving a residue (8 g.)
10. customThe solvent was removed
11. customthe product recrystallized from acetonitrile
12. customgiving a white solid