Reaktion #530917

Reaktionsgleichung

3,4-dimethoxyphenylacetic acid

EEDQ

α-(1-amino-1-methylethyl)-3-methoxybenzenemethanol

→

N-(β-hydroxy-3-methoxy-α,α-dimethylphenethyl)-3,4-dimethoxybenzeneacetamide

Ausbeute 72.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTetrahydrofuran is evaporated in vacuo
2. 2
   ExtraktionThe amide is extracted twice with 500 ml
3. 3
   WaschenThe combined organic extracts are washed with 500 ml
4. 4
   Trocknendilute aqueous NH4OH solution, dried (Na2SO4)
5. 5
   Sonstigeevaporated to dryness in vacuo
6. 6
   workup.DISSOLUTIONThe residual oil is dissolved in hot diethyl ether from which it
7. 7
   Sonstigecrystallizes
8. 8
   Sonstigeto give 72.0 g
9. 9
   SonstigeRecrystallization from diethyl ether
10. 10
    Sonstigegives 70 g

Vorschrift

A solution of 50 g. (0.26 mole) of 3,4-dimethoxyphenylacetic acid, 68 g. (0.28 mole) of EEDQ and 50 g. (0.26 mole) of α-(1-amino-1-methylethyl)-3-methoxybenzenemethanol in 450 ml. tetrahydrofuran are stirred for three days at 25° C., and then heated for 5 hours at 65° C. Tetrahydrofuran is evaporated in vacuo, and the residue is taken up with ice and 10% aqueous H2SO4 solution to pH 2. The amide is extracted twice with 500 ml. ethyl acetate. The combined organic extracts are washed with 500 ml. dilute aqueous NH4OH solution, dried (Na2SO4) and evaporated to dryness in vacuo. The residual oil is dissolved in hot diethyl ether from which it crystallizes to give 72.0 g. of impure product. Recrystallization from diethyl ether gives 70 g. (72% yield) of N-(β-hydroxy-3-methoxy-α,α-dimethylphenethyl)-3,4-dimethoxybenzeneacetamide as white crystals of analytical purity, m.p. 137°-138° C.

Quelle