Methanol → 3-Chloro-4,4-dimethoxybutan-2-one

Temperature

0 °C

To a solution of 297 g (5.5 mole) sodium methoxide in 5 liters of methanol at 0° C., is added in a slow stream 695 g (5.0 mole) 1,2-dichloro-1-buten-3-one. After the addition is complete, the mixture is stirred at 0° C. for one hour, an additional 54 g (1.0 mole) sodium methoxide is added, and stirring continued at 0° C. for one hour. The mixture is allowed to stir at room temperature overnight, another g mole of sodium methoxide added and stirring continued for an hour. The mixture is filtered (filter aid) to remove salts, washing with fresh methanol. The filtrate is concentrated in vacuo to a slurry which is taken up in isopropyl ether and washed in turn with water, saturated sodium bicarbonate solution and brine, then dried over anhydrous magnesium sulfate. The extract is concentrated in vacuo to provide a residual oil which is distilled in vacuo to afford a main fraction of 628 g (75%) of product, B.P. 66°-75° C. at 8 mm. 1H-NMR (CDCl3) ppm (delta): 2.33 (s, 3H), 3.43 (s, 3H), 3.47 (s, 3H), 4.23 (d, 1H), 4.63 (d, 1H).

1. additionAfter the addition
2. stirringstirring
3. waitcontinued at 0° C. for one hour
4. stirringto stir at room temperature overnight
5. stirringstirring
6. waitcontinued for an hour
7. filtrationThe mixture is filtered
8. filtration(filter aid)
9. customto remove salts
10. washwashing with fresh methanol
11. concentrationThe filtrate is concentrated in vacuo to a slurry which
12. washwashed in turn with water, saturated sodium bicarbonate solution and brine
13. dry with materialdried over anhydrous magnesium sulfate
14. concentrationThe extract is concentrated in vacuo
15. customto provide a residual oil which
16. distillationis distilled in vacuo

ORD record

ord-24b111684b274d2da2d02f671c50b9b2

Source dataset

uspto-grants-1984_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04482723