反应详情

温度

40 °C

Magnesium (4.6 g, 0.189 mol) together with tetrahydrofuran (65 ml) were placed in a reaction vessel and heated while stirring to 40° C. About 5% of a solution of 2-bromo-4-chloro-1-isopropylbenzene (IV) (43 g, 0.180 mol) in tetrahydrofuran (95 ml) is then added dropwise. After the reaction has commenced, the remainder of the 2-bromo-4-chloro-1-isopropylbenzene in tetrahydrofuran was added under gentle reflux over a period of 1 hour. The mixture was then cooled to 0° C. and dimethylformamide (13.8 g. 0.189 mol) was added dropwise over a period of 1 hour. The reaction mixture obtained was stirred for another 1 hour and hydrochloric acid (86.7 g, 0.369 mol) was added in such a way that the temperature was kept below 30° C. The phases were then separated and extracted with toluene (2×50 ml). The combined organic phases were distilled under reduced pressure and the crude product obtained was recrystallized from isopropanol/water 4:1. 5-Chloro-2-isopropylbenzaldehyde (25.7 g, 99 GC-% by area, 77% of theory) was obtained as a colourless solid.

1. temperatureheated
2. temperatureunder gentle reflux over a period of 1 hour
3. temperatureThe mixture was then cooled to 0° C.
4. customThe reaction mixture obtained
5. stirringwas stirred for another 1 hour
6. customwas kept below 30° C
7. customThe phases were then separated
8. extractionextracted with toluene (2×50 ml)
9. distillationThe combined organic phases were distilled under reduced pressure
10. customthe crude product obtained
11. customwas recrystallized from isopropanol/water 4:1