Bromine → Propanal, 2-bromo-3,3-dimethoxy-

To a solution of 25.0 g (0.19 mole) of 1,3,3-trimethoxy-1-propene in 75 ml of ether at 5° C is added 22.4 g (0.14 mole) of bromine (bromine color begins to persist at this point) over a period of 40 minutes. The solvent is removed in vacuo at 25° C and the colorless liquid residue is added dropwise with stirring to a mixture of 25 g of sodium bicarbonate and 80 ml of 75% v/v dioxane at 0°-5° C. Stirring is continued for 30 minutes and the mixture is extracted with 200 ml and 150 ml portions of ether. The extract is dried over magnesium sulfate, evaporated in vacuo and the residue distilled through a Vigreux head to afford 2-bromo-3,3-dimethoxypropionaldehyde, b.p. 70°-73° C/8 mm.

1. customof 40 minutes
2. customThe solvent is removed in vacuo at 25° C
3. additionthe colorless liquid residue is added dropwise
4. stirringStirring
5. extractionthe mixture is extracted with 200 ml and 150 ml portions of ether
6. dry with materialThe extract is dried over magnesium sulfate
7. customevaporated in vacuo
8. distillationthe residue distilled through a Vigreux head

ORD-Eintrag

ord-f9562bd8848b4b368141ce8dd0fb999d

Quelldatensatz

uspto-grants-1978_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04091087