Reaktion #95986

Reaktionsgleichung

agmatine-dichlorohydrate

dimethylformamide

triethylamine

→

L-prolyl-agmatine-dichlorohydrate

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONadded
2. 2
   SonstigeThe reaction mixture is evaporated at reduced pressure
3. 3
   workup.DISSOLUTIONThe residue is dissolved in a mixture of 50 ml of 0.1 N hydrochloric acid and 20 ml of ethyl acetate
4. 4
   Extraktionthe aqueous layer is extracted twice with 20 ml of diethyl ether
5. 5
   Extraktionextracted five times with 20 ml of chloroform
6. 6
   WaschenThe combined chloroform layers are washed twice with water
7. 7
   Sonstigeevaporated at reduced pressure
8. 8
   workup.DISSOLUTIONThe evaporation residue, benzyloxycarbonyl-L-prolyl-agmatine-hydrochloride (RF3 0.32 to 0.42), is dissolved in 40 ml of methanol
9. 9
   workup.ADDITION10 ml of 1 N hydrochloric acid added
10. 10
    Filtrationthe catalyst is filtered
11. 11
    Waschenwashed with water
12. 12
    Sonstigethe filtrate evaporated at reduced pressure
13. 13
    Filtrationfiltered
14. 14
    Waschenwashed with diethyl ether
15. 15
    Trocknendried over potassium hydroxide at reduced pressure
16. 16
    Sonstige[α]D20 =-33.25° (c=1, methanol)

Vorschrift

3.7 g (10 mmoles) of benzyloxycarbonyl-L-prolyl-p-nitrophenyl ester (Goodman and Stueben: J. Am. Chem. Soc., 81, 3980, 1959) are dissolved in a mixture of 10 ml of dimethylformamide and 5 ml of pyridine, 2.03 g (10 mmoles) of agmatine-dichlorohydrate (in formula II A represents an H2N--C(NH)-- residue, B a chlorine atom and n=2) and 1.4 ml (10 mmoles) of triethylamine added, and stirred for 16 to 20 hours. The reaction mixture is evaporated at reduced pressure. The residue is dissolved in a mixture of 50 ml of 0.1 N hydrochloric acid and 20 ml of ethyl acetate, the aqueous layer is extracted twice with 20 ml of diethyl ether, neutralized with solid sodium hydrogen carbonate and then extracted five times with 20 ml of chloroform. The combined chloroform layers are washed twice with water and evaporated at reduced pressure. The evaporation residue, benzyloxycarbonyl-L-prolyl-agmatine-hydrochloride (RF3 0.32 to 0.42), is dissolved in 40 ml of methanol, 10 ml of 1 N hydrochloric acid added, and the mixture hydrogenated in the presence of palladium charcoal. When the reaction is concluded, the catalyst is filtered, washed with water, and the filtrate evaporated at reduced pressure. The evaporation residue is worked up with diethyl ether, filtered, washed with diethyl ether and dried over potassium hydroxide at reduced pressure. Yield: 2.1 g (70 percent) of the named compound. M.p.: 186° to 189° C.; RF4 0.15 to 0.25; [α]D20 =-33.25° (c=1, methanol).

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