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 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 have appeared are filtered off and the filtrate is evaporated under reduced pressure (20 mm Hg) at 45° C. The resulting residue and the crystals which have been separated beforehand are dissolved in methylene chloride (750 cc). The organic solution is washed 4 times with distilled water (600 cc in total), dried over sodium sulphate and evaporated. The resulting product (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 first 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 resulting product (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 I.R. spectroscopy in petroleum jelly), which melts at 111° C., is obtained.

1. filtrationThe crystals which have appeared are filtered off
2. customthe filtrate is evaporated under reduced pressure (20 mm Hg) at 45° C
3. customThe resulting residue and the crystals which have been separated
4. dissolutionare dissolved in methylene chloride (750 cc)
5. washThe organic solution is washed 4 times with distilled water (600 cc in total)
6. dry with materialdried over sodium sulphate
7. customevaporated
8. dissolutionThe resulting product (98.0 g) is dissolved in chloroform (400 cc)
9. customThe solution is chromatographed on a column of diameter 6.8 cm
10. additioncontaining silica (0.063-0.2 mm, 800 g)
11. washElution
12. customwith chloroform (7.2 liters), this eluate being collected
13. customevaporated to dryness
14. customThe resulting product (85.0 g) is purified by recrystallisation from acetonitrile (350 cc)