1-Heptyne → 1,1-Dimethoxynon-3-yne

Temperature

0 °C

1-Heptyne (50 ml, 381 mmole) is dissolved in 360 ml dry THF in a flame dried 2000 ml 3-neck round bottom flask under nitrogen. The solution is cooled to 0° C. and treated with n-butyllithium (232 ml, 360 mmole) dropwise over 40 minutes via a dropping funnel. The reaction mixture is stirred 30 minutes at 0° C., treated with hexamethylphosphoric triamide (68 ml, 391 mmole), and stirred an additional 30 minutes at 0° C. 1,1-Dimethoxy-2-bromoethane (43 ml, 364 mmole) is added dropwise to the reaction mixture over 10 minutes at 0° C. The reaction mixture is stirred 3 hours at 0° C. and an additional 72 hours at room temperature. The mixture is subsequently quenched with 5 ml water and the THF removed in vacuo. The amber oily residue is dissolved in 200 ml diethyl ether and poured into 100 ml 50% saturated sodium chloride. The aqueous layer is extracted with 3×75 ml diethyl ether. The organics are combined, washed with 6×50 ml 50% saturated sodium chloride, and dried over anhydrous magnesium sulfate. The diethyl ether is removed in vacuo and the red oily residue distilled under reduced pressure. After a 5 ml forerun, the fraction boiling at 65°-67° C. (0.5 mm) is collected to provide 42 g of the title compound as a colorless oil. Following the above procedure gives the title compound having the physical characteristic described below:

1. customdried 2000 ml 3-neck round bottom flask under nitrogen
2. stirringstirred an additional 30 minutes at 0° C
3. stirringThe reaction mixture is stirred 3 hours at 0° C. and an additional 72 hours at room temperature
4. customThe mixture is subsequently quenched with 5 ml water
5. customthe THF removed in vacuo
6. dissolutionThe amber oily residue is dissolved in 200 ml diethyl ether
7. additionpoured into 100 ml 50% saturated sodium chloride
8. extractionThe aqueous layer is extracted with 3×75 ml diethyl ether
9. washwashed with 6×50 ml 50% saturated sodium chloride
10. dry with materialdried over anhydrous magnesium sulfate
11. customThe diethyl ether is removed in vacuo
12. distillationthe red oily residue distilled under reduced pressure
13. customAfter a 5 ml forerun, the fraction boiling at 65°-67° C. (0.5 mm) is collected

ORD record

ord-77e644e687e443098f8c57c43291499c

Source dataset

uspto-grants-1992_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05116981