Reaktion #1269841

Reaktionsgleichung

Ethyl formate

sarcosin methyl ester hydrochloride

NaH

HCl

HCl

K2CO3

ethanol

H2NCN

sodium acetate

→

1-N-methyl-2-amino imidazole-5-carboxylic acid ethyl ester

Lösungsmittel

HOAc

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto reaction)
2. 2
   Sonstigecontained in a 1-L round-bottomed flask
3. 3
   TemperaturThe reaction mixture was cooled in an ice-water bath
4. 4
   workup.ADDITIONadded slowly during a period of 2 h
5. 5
   workup.STIRRINGstirred at rt for about 14 h
6. 6
   SonstigeVolatiles were removed
7. 7
   Sonstigea rotary evaporator
8. 8
   Sonstigeto yield a residue which
9. 9
   Sonstigewas triturated twice with hexane (500 mL)
10. 10
    Sonstigeto yield a sticky light brown paste which
11. 11
    TemperaturAfter the reaction mixture cooled
12. 12
    Filtrationthe white precipitate was filtered off
13. 13
    Waschenthe residue washed with 2×25 mL of ethanol
14. 14
    SonstigeThe filtrate was evaporated
15. 15
    Sonstigeto yield a thick brown oil to which
16. 16
    workup.STIRRINGThe reaction mixture was stirred at 90-100° C. for 1.5 h
17. 17
    Sonstigeto yield a clear solution which
18. 18
    Temperaturwas cooled
19. 19
    Einengenthe resulting solution concentrated
20. 20
    Sonstigea rotary evaporator at a temperature not more than 45° C
21. 21
    SonstigeThe concentrated reaction mixture
22. 22
    Extraktionextracted with EA (5×200 mL followed by 3×50 mL)
23. 23
    TrocknenThe combined ethyl acetate layers were dried over MgSO4
24. 24
    Filtrationfiltered
25. 25
    Sonstigevolatiles removed

Vorschrift

Ethyl formate (500 mL) was added to sarcosin methyl ester hydrochloride (82 g, 585.7 mmol, grounded into powder prior to reaction) contained in a 1-L round-bottomed flask. The reaction mixture was cooled in an ice-water bath, stirred, a gas outlet connected with the flask, NaH (60% oil suspension, 54 g, 1.35 mol) added slowly during a period of 2 h, and stirred at rt for about 14 h. Volatiles were removed using a rotary evaporator to yield a residue which was triturated twice with hexane (500 mL) to yield a sticky light brown paste which was dissolved in ethanol (400 mL) and conc. HCl (50 mL) and stirred at 110° C. for 1.5 h. After the reaction mixture cooled, the white precipitate was filtered off and the residue washed with 2×25 mL of ethanol. The filtrate was evaporated to yield a thick brown oil to which was added 10% aqueous HOAc, H2NCN (45 g, 1.07 mol), and sodium acetate (88 g, 1.07 mol). The reaction mixture was stirred at 90-100° C. for 1.5 h to yield a clear solution which was cooled, its pH adjusted to 1 using concentrated HCl and the resulting solution concentrated to ⅕ its original volume using a rotary evaporator at a temperature not more than 45° C. The concentrated reaction mixture was carefully neutralized by addition of K2CO3 to a pH of 8-9 and extracted with EA (5×200 mL followed by 3×50 mL). The combined ethyl acetate layers were dried over MgSO4, filtered, and volatiles removed to yield 48 g of 1-N-methyl-2-amino imidazole-5-carboxylic acid ethyl ester.

Quelle