Reaktion #536365

Reaktionsgleichung

methyl carbamate

2-oxo-4-(hydroxymethylphosphinyl)-butanoic acid

acetic acid

→

objective compound

Ausbeute 72.2%

(Z)-2-methoxycarbonylamino-4-(hydroxymethylphosphinyl)-2-butenoic acid

Ausbeute 72.2%

Lösungsmittel

chlorobenzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISSOLUTIONAfter being dissolved
2. 2
   Temperaturby heating
3. 3
   Temperaturthe solution was refluxed with vigorous stirring
4. 4
   SonstigeA remaining solution was removed appropriately while the internal temperature of the reaction solution
5. 5
   Temperaturwas maintained from 106 to 110 deg. C
6. 6
   workup.ADDITIONby adding chlorobenzene
7. 7
   SonstigeTwo hours
8. 8
   SonstigeAfter removing about 50 mL of the solvent under a reduced pressure
9. 9
   workup.ADDITIONby adding 20 mL of acetic acid
10. 10
    SonstigeThe precipitate which was obtained
11. 11
    workup.STIRRINGstirring over-night
12. 12
    Filtrationwas filtered
13. 13
    Waschenthe filtrate was washed with acetic acid
14. 14
    WaschenAfter being washed with acetone
15. 15
    Sonstigedried for 6 hours from 40 to 50 deg. C

Vorschrift

5.835 g of methyl carbamate, 0.275 g of p-toluenesulfonic acid monohydrate and 10.000 g of 2-oxo-4-(hydroxymethylphosphinyl)-butanoic acid were added to 16 mL of acetic acid to be suspended. After being dissolved by heating, 80 mL of chlorobenzene was added thereto and then the solution was refluxed with vigorous stirring. A remaining solution was removed appropriately while the internal temperature of the reaction solution was maintained from 106 to 110 deg. C. under a slightly reduced pressure, followed by adding chlorobenzene, the volume of which was equal to the volume of the removed solution. Two hours later, dissipation of almost all the raw materials was confirmed by HPLC measurement. At this point, the area ratio of Z form to E form was 93:7. After removing about 50 mL of the solvent under a reduced pressure, followed by adding 20 mL of acetic acid, and then the resultant was stirred for 1 hour at 80 deg. C. The precipitate which was obtained by cooling the solution gradually to room temperature and stirring over-night, was filtered and then the filtrate was washed with acetic acid. After being washed with acetone, dried for 6 hours from 40 to 50 deg. C. under a reduced pressure, 9.505 g of the objective compound was obtained (72.2% yield, Z:E=99.5:0.5).

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