Reaktion #214811

Reaktionsgleichung

N-(2-benzoylthiopropanoyl)-N-cyclopropylglycine tert-butyl ester

DCHA

→

N-(2-Benzoylthiopropanoyl)-N-cyclopropylglycine

Lösungsmittel

anisole

trifluoroacetic acid

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTrifluoroacetic acid was removed in vacuo
2. 2
   SonstigeThe aqueous bicarbonate phase was separated
3. 3
   Waschenwashed twice with ethyl acetate
4. 4
   ExtraktionThe precipitated product was extracted into chloroform
5. 5
   Waschenwashed twice with water
6. 6
   TrocknenThe organic phase was dried over magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   Sonstigeevaporated
9. 9
   Sonstigeto give crude product as a pale yellow oil
10. 10
    Sonstigeto give colorless crystals, m.p. 140°-143° C.

Vorschrift

Crude N-(2-benzoylthiopropanoyl)-N-cyclopropylglycine tert-butyl ester (17.1 g) was dissolved in a mixture of anisole (25 ml) and trifluoroacetic acid (100 ml). The resulting solution was stirred at room temperature for two hours. Trifluoroacetic acid was removed in vacuo and the residue was distributed between ethyl acetate and saturated sodium bicarbonate. The aqueous bicarbonate phase was separated and washed twice with ethyl acetate and then acidified cautiously to pH 4-6 with concentrated hydrochloric acid. The precipitated product was extracted into chloroform and washed twice with water. The organic phase was dried over magnesium sulfate, filtered and evaporated to give crude product as a pale yellow oil. The product was characterized as its DCHA salt which was prepared in ether to give colorless crystals, m.p. 140°-143° C.

Quelle