反应详情

Potassium salt from Procedure 5 (396 g) was slurried with DMF (8 l) and added to a 1 l flask containing 800 g potassium carbonate. Dimethyl sulfate (420 ml) was added in portions at 60° over 1 hour and the reaction was stirred at 60° overnight. The K2CO3 was washed with acetone and the washings were added to the distillation residue and again solvent was removed in vacuo. The dry residue was treated with water (1 l) and extracted with CH2Cl2. The extracts were dried, evaporated, and the product was crystallized from methanol to afford the product, (335 g, 94%) mp 109°-111° C.

1. additionadded to a 1 l flask
2. washThe K2CO3 was washed with acetone
3. additionthe washings were added to the distillation residue and again solvent
4. customwas removed in vacuo
5. additionThe dry residue was treated with water (1 l)
6. extractionextracted with CH2Cl2
7. customThe extracts were dried
8. customevaporated
9. customthe product was crystallized from methanol
10. customto afford the product, (335 g, 94%) mp 109°-111° C.