Reaktion #57989

Reaktionsgleichung

(2-Hydroxyethyl)carbamic acid tert-butyl ester

4-hydroxybenzoic acid methyl ester

diisopropyl azodicarboxylate

Acetyl Chloride

Triphenylphosphine

→

4-(2-aminoethoxy)benzoic acid methyl ester hydrochloride

Ausbeute 93.5%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe reaction temperature below 10° C
2. 2
   workup.ADDITIONAfter addition
3. 3
   Temperaturto warm slowly to ambient temperature
4. 4
   SonstigeAfter completion of reaction, solvent
5. 5
   workup.DISTILLATIONwas distilled under reduced pressure
6. 6
   workup.DISSOLUTIONthe resulting oil was dissolved in ethanol (500 ml)
7. 7
   Sonstigeto rise to 40° C
8. 8
   workup.STIRRINGThe resulting suspension was stirred at 40° C. until completion of reaction
9. 9
   SonstigeAfter completion of reaction
10. 10
    Filtrationthe resulting crystals were filtered on a coarse frit
11. 11
    Waschenwashed with ethyl Acetate (300 mL)
12. 12
    SonstigeThe material is dried in vacuo

Vorschrift

(2-Hydroxyethyl)carbamic acid tert-butyl ester (152.0 g, 0.942 mol) and 4-hydroxybenzoic acid methyl ester (174.0 g, 1.12 mol) were dissolved in tetrahydrofuran (2000 ml) and cooled to 0-5° C. Triphenylphosphine (292.8 g 1.116 mol) was added to the cooled mixture. A solution of diisopropyl azodicarboxylate (246.0 g, 1.218 mol) in tetrahydrofuran (400 ml) was added dropwise over a period of one to two hours keeping the reaction temperature below 10° C. After addition, the reaction was allowed to warm slowly to ambient temperature and stirred overnight. After completion of reaction, solvent was distilled under reduced pressure and the resulting oil was dissolved in ethanol (500 ml) and ethyl acetate (2000 ml). Acetyl Chloride (222.0 g, 2.826 mol) was added drop wise over fifteen minutes with the temperature allowed to rise to 40° C. The resulting suspension was stirred at 40° C. until completion of reaction. After completion of reaction, the resulting crystals were filtered on a coarse frit and washed with ethyl Acetate (300 mL). The material is dried in vacuo to give of 4-(2-aminoethoxy)benzoic acid methyl ester hydrochloride (204.1 g) as a white crystalline solid.

Quelle