Dimethyl Sulfoxide → rac-6-acetyl-3,4-dihydro-7-[(5-acetoxypentyl)oxy]-2 H-1-benzopyran-2-carboxylic acid methyl ester

HRID 359939

Reaktionsgleichung

Reaktionsgleichung von HRID 359939
[C:1]([O:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9]Br)(=[O:3])[CH3:2].CS(C)=O.[CH3:15][O:16][C:17]([CH:19]1[CH2:24][CH2:23][C:22]2[CH:25]=[C:26]([C:30](=[O:32])[CH3:31])[C:27]([OH:29])=[CH:28][C:21]=2[O:20]1)=[O:18].C(=O)([O-])[O-].[K+].[K+]>O>[CH3:15][O:16][C:17]([CH:19]1[CH2:24][CH2:23][C:22]2[CH:25]=[C:26]([C:30](=[O:32])[CH3:31])[C:27]([O:29][CH2:9][CH2:8][CH2:7][CH2:6][CH2:5][O:4][C:1](=[O:3])[CH3:2])=[CH:28][C:21]=2[O:20]1)=[O:18]

Komponenten

6

Edukt 4

HCID 679Dimethyl SulfoxideHCID 11430Potassium CarbonateHCID 851405-Bromopentyl acetateHCID 11747049rac-6-acetyl-3, 4-dihydro-7-hydroxy-2H-1-benzopyran-2-carboxylic acid methyl ester

Produkt 1

HCID 10872550rac-6-acetyl-3,4-dihydro-7-[(5-acetoxypentyl)oxy]-2 H-1-benzopyran-2-carboxylic acid methyl ester

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Versuchsvorschrift

A 12-L three-neck, round-bottom flask equipped with a mechanical stirrer and a nitrogen bubbler, was charged with 375.0 g (1.79 moles) of 5-bromo-1-pentanyl acetate, 3.5 L of dimethyl sulfoxide, 407.0g (1.63 moles) of rac-6-acetyl-3, 4-dihydro-7-hydroxy-2H-1-benzopyran-2-carboxylic acid methyl ester and 510.0 g of anhydrous granular potassium carbonate in finely powdered form. The mixture was stirred at room temperature under nitrogen for 19 hours, poured into an extractor containing 10 L of deionized water, and extracted with 2×4 L and 1×2 L=10 L of ethyl acetate. The organic layer was washed with 2×4 L=8 L of 1:1 deionized water-saturated brine, followed by 2 L of saturated brine, dried (anhydrous sodium sulfate), and filtered. The solvent was removed at 45° /70 mm and then under high vacuum to give 648.3 g of crude rac-6-acetyl-3,4-dihydro- 7-[(5-acetoxypentyl)oxy]-2H-1-benzopyran-2-carboxylic acid methyl ester. The crude product was dissolved in 2 L of anhydrous ether and the solution was poured into a 12 L three-neck flask equipped with a mechanical stirrer. The stirred solution was cooled in an ice-bath and 2 L of petroleum ether (35°-60° ) was slowly added, which resulted in the formation of a precipitate heavy enough to stop the stirrer. The solid was broken with a spatula and stirring was continued in the ice-bath for 1 hour. The product was collected by filtration, washed with cold (3° ) 1:1 ether-petroleum ether, and dried at room temperature under high vacuum to give 601.5 g (97.7& yield) of rac-6-acetyl-3,4-dihydro-7-[(5-acetoxypentyl)oxy]-2H-1-benzopyran-2-carboxylic acid methyl ester as a white powder, mp 37°-49° C. UV (EtOH): λmax, 312 (ε=7,200), 268 (ε=11,200), 230 (ε=16,900), and 216 (ε=19,000) nm; MS: m/z 378 (M+, 40).

Aufarbeitung

  1. customA 12-L three-neck, round-bottom flask equipped with a mechanical stirrer
  2. additionpoured into an extractor
  3. extractionextracted with 2×4 L and 1×2 L=10 L of ethyl acetate
  4. washThe organic layer was washed with 2×4 L=8 L of 1:1 deionized water-saturated brine
  5. dry with materialdried (anhydrous sodium sulfate)
  6. filtrationfiltered
  7. customThe solvent was removed at 45° /70 mm

Quellen und Nachweise

ORD-Eintrag
ord-3f004c8f1c0c480e8b34a7092a7777a6
Quelldatensatz
uspto-grants-1991_03
Patentnummer
US05003090

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