1-[2,5-Dimethoxy-3,6-bis(methoxymethoxy)phenyl]-2-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)ethane → Ethyl 4-[2,5-dimethoxy-3,6-bis(methoxymethoxy)phenyl]butyrate

Temperature

100 °C

2.9 Grams of 1-[2,5-dimethoxy-3,6-bis(methoxymethoxy)phenyl]-2-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)ethane was dissolved in a mixed solvent of 90 ml of methanol with 90 ml of ethyl acetate, then under an ice-cooled condition, 3 g of sodium boron hydride was added thereto. 1 Hour later, the reaction mixture was concentrated under a reduced pressure, to the residue obtained was added 300 ml of ethyl acetate, and this mixture was washed twice with 200 ml of water, further washed twice with 200 ml of a saturated sodium chloride aqueous solution, then dried over anhydrous magnesium sulfate. The dehydrated ethyl acetate solution was concentrated under a reduced pressure to obtain the residue, and the residue was dissolved in a mixed solvent of 20 ml of ethanol with 40 ml of pyridine, then a catalytic amount of copper powder was added thereto and the mixture was heated at 100° C. in an oil bath and stirred for 8 hours. The reaction mixture was concentrated under a reduced pressure, to the residue thus obtained was added 300 ml of ethyl acetate, then the solution was washed twice with 200 ml of a diluted aqueous solution of hydrochloric acid (pH 3), further washed 4 times with 200 ml of water, next washed twice with 200 ml of a saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, then concentrated under reduced pressure. The residue thus obtained was purified by a silica gel column chromatography (diameter 5 cm×length 15 cm, eluent: 40% ethyl acetate-n-hexane solution, "Wakogel C-200") to yield 1.9 g of ethyl 4-[2,5-dimethoxy-3,6-bis(methoxymethoxy)phenyl]butyrate. Colorless oily substance.

1. additionwas added
2. concentration1 Hour later, the reaction mixture was concentrated under a reduced pressure, to the residue
3. customobtained
4. washthis mixture was washed twice with 200 ml of water
5. washfurther washed twice with 200 ml of a saturated sodium chloride aqueous solution
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationThe dehydrated ethyl acetate solution was concentrated under a reduced pressure
8. customto obtain the residue
9. concentrationThe reaction mixture was concentrated under a reduced pressure, to the residue
10. customthus obtained
11. washthe solution was washed twice with 200 ml of a diluted aqueous solution of hydrochloric acid (pH 3)
12. washfurther washed 4 times with 200 ml of water
13. washnext washed twice with 200 ml of a saturated sodium chloride aqueous solution
14. dry with materialdried over anhydrous sodium sulfate
15. concentrationconcentrated under reduced pressure
16. customThe residue thus obtained
17. customwas purified by a silica gel column chromatography (diameter 5 cm×length 15 cm, eluent: 40% ethyl acetate-n-hexane solution, "Wakogel C-200")

ORD record

ord-5cf50c41b01d4650b85f7f9b78d85996

Source dataset

uspto-grants-1993_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05220042