تفاعل #2779

معادلة التفاعل

HCl

7-(tetraacetyl-β-galactosyl)-4-methylcoumarin-3-acetic acid, ethyl ester

7-(Tetraacetyl-β-galactosyl)-4-methylcoumarin-3-acetic acid, ethyl ester

KOH

→

4

المردود 60.4%

7-(β-galactosyl)-4-methylcoumarin-3-acetic acid

المردود 60.4%

المذيبات

methanol

ظروف التفاعل

المعالجة

1. 1
   أخرىevaporated to dryness under reduced pressure
2. 2
   workup.DISSOLUTIONThe residue was dissolved in water (10 mL)
3. 3
   غسيلThe C18Sep Pack Cartridge (Waters Part No. 65910) was washed with methanol (3 mL) and water (3 mL) before the sample
4. 4
   غسيلThe cartridge was then washed with water (3 mL)
5. 5
   أخرىto remove any salt
6. 6
   غسيلeluted the desired product
7. 7
   أخرىevaporated under reduced pressure
8. 8
   أخرىthe while solid obtained
9. 9
   أخرىwas recrystallized from ethanol/water

الإجراء التجريبي

To a stirred solution of 7-(tetraacetyl-β-galactosyl)-4-methylcoumarin-3-acetic acid, ethyl ester (3) (422 mg, 0.712 mmol) in methanol was added 6.8M KOH (5 mL) and the solution was stirred overnight at room temperature. The solution was neutralized by the addition of 1N HCl and evaporated to dryness under reduced pressure. The residue was dissolved in water (10 mL) and desalted using C18Sep Pack Cartridges in 10×1 mL portions. The C18Sep Pack Cartridge (Waters Part No. 65910) was washed with methanol (3 mL) and water (3 mL) before the sample was applied in 1 mL. The cartridge was then washed with water (3 mL) to remove any salt followed by metahnol (3 mL) which eluted the desired product as determined by TLC (silica gel, acetone:20 mM NaOAc 9:1). The methanol washes were pooled and evaporated under reduced pressure and the while solid obtained was recrystallized from ethanol/water to give 170 mg (0.43 mmol, 60%) of 4 as white crystals: m.p. 186°-188° C.

المصدر