Chloroacetaldehyde → 4,5,6,7-Tetrahydro-1-benzofuran-4-one

To a mixture of 80 ml of water and 20 ml of 40% aqueous solution of chloroacetaldehyde was added 10.0 g (119 mmoles) of sodium hydrogencarbonate while cooling with ice. To the resulting reaction mixture was added dropwise 90 ml of aqueous solution containing 11.2 g (100 mmoles) of 1,3-cyclohexanedione while cooling with ice at a rate of 0.4 ml/minute. The reaction mixture was maintained at a pH of from 9 to 6 throughout the reaction. After completing the dropping, the reaction mixture was stirred at a room temperature overnight. To the resulting reaction mixture was added about 100 ml of ethyl acetate, and then the reaction mixture was acidified (pH<1) with sulfuric acid and stirred for about one hour. The ethyl acetate layer was separated, washed with an aqueous solution of potassium carbonate, and dried on magnesium sulfate. After distilling away the ethyl acetate, the obtained residue was distilled under a reduced pressure to give 10.3 g (yield: 76%) of 4-oxo-4,5,6,7 -tetrahydrobenzofuran being a colorless oily material (boiling point: 66° C./1 torr).

1. temperaturewhile cooling with ice
2. customTo the resulting reaction mixture
3. temperaturewhile cooling with ice at a rate of 0.4 ml/minute
4. temperatureThe reaction mixture was maintained at a pH of from 9 to 6 throughout the reaction
5. customTo the resulting reaction mixture
6. stirringstirred for about one hour
7. customThe ethyl acetate layer was separated
8. washwashed with an aqueous solution of potassium carbonate
9. customdried on magnesium sulfate
10. distillationAfter distilling away the ethyl acetate
11. distillationthe obtained residue was distilled under a reduced pressure

ORD-Eintrag

ord-08050c378b644ee2a3037ac7dfa67663

Quelldatensatz

uspto-grants-1985_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04558143