反应详情

A solution of 2,2-dimethylpent-4-en-3-one (30.0 g) in anhydrous acetonitrile (60 cc) is added, at a maximum temperature of 5° C., to a suspension of triethylammonium 5-chloropyrid-2-yldithiocarbamate (82.0 g) in anhydrous acetonitrile (400 cc). The reaction is allowed to proceed for 3 hours at between 5° and 20° C. The crystals which appear are filtered off; the filtrate is evaporated under reduced pressure (20 mmHg) at 45° C. The residue obtained and the crystals separated off beforehand are dissolved in methylene chloride (750 cc). The organic solution is washed four times with distilled water (total 600 cc), dried over sodium sulphate and evaporated. The product obtained (98.0 g) is dissolved in chloroform (400 cc). The solution is chromatographed on a column of diameter 6.8 cm, containing silica (0.063-0.2 mm; 800 g). Elution is carried out with chloroform (2.6 liters), this eluate being discarded, and then with chloroform (7.2 liters), this eluate being collected and evaporated to dryness. The product obtained (85.0 g) is purified by recrystallisation from acetonitrile (350 cc). 4,4-Dimethyl-3-oxopentyl 5-chloropyrid-2-yldithiocarbamate (70.0 g) (structure determined by IR spectroscopy in petroleum jelly), which melts at 111° C., is obtained.

1. filtrationThe crystals which appear are filtered off
2. customthe filtrate is evaporated under reduced pressure (20 mmHg) at 45° C
3. customThe residue obtained
4. customthe crystals separated off beforehand
5. dissolutionare dissolved in methylene chloride (750 cc)
6. washThe organic solution is washed four times with distilled water (total 600 cc)
7. dry with materialdried over sodium sulphate
8. customevaporated
9. customThe product obtained (98.0 g)
10. customThe solution is chromatographed on a column of diameter 6.8 cm
11. additioncontaining silica (0.063-0.2 mm; 800 g)
12. washElution
13. customwith chloroform (7.2 liters), this eluate being collected
14. customevaporated to dryness
15. customThe product obtained (85.0 g)
16. customis purified by recrystallisation from acetonitrile (350 cc)