Reaktion #312379

Reaktionsgleichung

isobutyl chloroformate

N-methyl-morpholine

acetic acid

1,6-dimethyl-8β-hydrazinomethyl-ergoline

→

1,6-dimethyl-8β-[(N'-acetyl-hydrazino)-methyl]-ergoline

Ausbeute 60.4%

Lösungsmittel

acetonitrile

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONis added to the mixture
2. 2
   Sonstige(within 30 minutes)
3. 3
   Temperaturwarmed to room temperature
4. 4
   workup.STIRRINGstirred at room temperature for 2 hours
5. 5
   Sonstigeevaporated in vacuo
6. 6
   workup.DISSOLUTIONThe residue is dissolved in 200 ml of chloroform
7. 7
   workup.ADDITION100 ml of water are added
8. 8
   workup.STIRRINGthe mixture is shaken
9. 9
   SonstigeThe organic phase is separated
10. 10
    Extraktionthe aqueous phase is extracted thrice with 100 ml of chloroform
11. 11
    Sonstigeevaporated to dryness in vacuo
12. 12
    Sonstigeto remove the occasional impurities
13. 13
    Waschenis eluted with a 30:0.3:9 mixture of chloroform, water and methanol
14. 14
    workup.ADDITIONThe fractions containing a substance with an Rf value of 0.75
15. 15
    Sonstigeevaporated in vacuo
16. 16
    Sonstigethe residue is crystallized from alcohol

Vorschrift

0.6 g of acetic acid are dissolved in 25 ml of acetonitrile with stirring. The solution is cooled to -15° C., and 1.39 ml of isobutyl chloroformate and 1.1 ml of N-methyl-morpholine are added. After 5 minutes of stirring a solution of 2.8 g of 1,6-dimethyl-8β-hydrazinomethyl-ergoline in 10 ml of acetonitrile is added to the mixture. The mixture is slowly (within 30 minutes) warmed to room temperature, stirred at room temperature for 2 hours, then evaporated in vacuo. The residue is dissolved in 200 ml of chloroform, and 100 ml of water are added. The pH of the aqueous phase is adjusted to 8 with 10% aqueous ammonia, and the mixture is shaken. The organic phase is separated, and the aqueous phase is extracted thrice with 100 ml of chloroform. The chloroform fractions are combined and evaporated to dryness in vacuo. The residue is subjected to column chromatography in order to remove the occasional impurities. 60 g of silica gel are used as adsorbent, and the column is eluted with a 30:0.3:9 mixture of chloroform, water and methanol. The effluent is analyzed by thin layer chromatography. The fractions containing a substance with an Rf value of 0.75 are combined, evaporated in vacuo, and the residue is crystallized from alcohol. 1.9 g (60.4%) of 1,6-dimethyl-8β-[(N'-acetyl-hydrazino)-methyl]-ergoline are obtained; m.p.: 190°-192° C., [α]D20 =-29.7° (c=1, in 96% ethanol).

Quelle