반응 #2080902

반응 방정식

2,3,4-tri-O-acetyl-5-thio-D-xylopyranosyl bromide

2-acetyl-7-hydroxybenzofuran

toluene

sodium hydroxide

→

desired product

수율 37.0%

2-acetyl-7-benzofuranyl 2,3,4-tri-O-acetyl-5-thio-β-D-xylopyranoside

수율 37.0%

용매

triethylamine

acetonitrile

반응 조건

후처리

1. 1
   기타is brought to 90° C.
2. 2
   온도The mixture maintained at 90° C.
3. 3
   온도The mixture is subsequently cooled
4. 4
   workup.STIRRINGthe resulting mixture is stirred for one hour
5. 5
   여과The medium is filtered
6. 6
   세척the precipitate is washed with ethyl acetate
7. 7
   기타The filtrate is subsequently separated
8. 8
   세척The organic phase is washed with a saturated aqueous solution of ammonium chloride
9. 9
   건조dried over magnesium sulfate
10. 10
    농축concentrated under reduced pressure
11. 11
    기타The evaporation residue is purified by silica gel chromatography, elution

실험 절차

A mixture composed of 1.93 g (14.1 mM) of anhydrous zinc chloride, 1 g (5.7 mM) of 2-acetyl-7-hydroxybenzofuran and 2.2 g of molecular sieve 13× is stirred into 13 ml of toluene and 13 ml of acetonitrile. The mixture is brought to 90° C. and 1.42 g (14.1 mM) of triethylamine and 2.22 g (6.27 mM) of 2,3,4-tri-O-acetyl-5-thio-D-xylopyranosyl bromide are added, while maintaining the mixture at the temperature of 90° C. The mixture maintained at 90° C. is then stirred for 20 minutes. The mixture is subsequently cooled, 65 ml of a 0.5 N solution of sodium hydroxide are added, and the resulting mixture is stirred for one hour. The medium is filtered and the precipitate is washed with ethyl acetate. The filtrate is subsequently separated by settling out. The organic phase is washed with a saturated aqueous solution of ammonium chloride, dried over magnesium sulfate, and concentrated under reduced pressure. The evaporation residue is purified by silica gel chromatography, elution being carried out with a cyclohexane/ethyl acetate mixture (7/3; v/v). The desired product is obtained in the form of a yellowish solid with a yield of 37%.

출처