Reaktion #64789

Reaktionsgleichung

N-methylmorpholine

isobutylchloroformate

N-[[(1,1-dimethylethyl)oxy]carbonyl]-L-phenylalanine

diazomethane

→

(S)-3-[[[(1,1-Dimethylethyl)oxy]carbonyl]amino]-2-oxo-1-diazo-4-phenylbutane

Lösungsmittel

methanol

tetrahydrofuran

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe reaction mixture was then filtered into a flask
2. 2
   Temperaturlet warm to -5° C.
3. 3
   workup.STIRRINGstirred overnight
4. 4
   SonstigeThe cold reaction mixture
5. 5
   Filtrationwas then filtered
6. 6
   Waschenthe filtrate was washed with water, saturated sodium bicarbonate, and brine
7. 7
   TrocknenThe organic layer was dried (MgSO4)
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated in vacuo
10. 10
    Sonstigeto yield a reddish brown oil
11. 11
    SonstigeThe oil was triturated with cold petroleum ether
12. 12
    Sonstigeto yield 14.42 g
13. 13
    EinengenThe mother liquors were concentrated
14. 14
    Sonstigeto stand yielding a second crop of 1.96 g

Vorschrift

A solution of N-[[(1,1-dimethylethyl)oxy]carbonyl]-L-phenylalanine (20.01 g., 75 mmol) in 150 mL of dry tetrahydrofuran was chilled to -25° C. and treated with N-methylmorpholine (8.3 mL, 75 mmol) and isobutylchloroformate (9.8 mL, 75 mmol) and then stirred at -25° C. for 10 minutes. The reaction mixture was then filtered into a flask containing a solution of diazomethane (prepared from 35.48 g., 240 mmol of N-methyl-N'-nitro-N-nitrosoguanidine) in 300 mL of anhydrous ether at -78° C. and then let warm to -5° C. and stirred overnight. The cold reaction mixture was then filtered and the filtrate was washed with water, saturated sodium bicarbonate, and brine. The organic layer was dried (MgSO4), filtered and concentrated in vacuo to yield a reddish brown oil. The oil was triturated with cold petroleum ether to yield 14.42 g. of a light tan solid. The mother liquors were concentrated and allowed to stand yielding a second crop of 1.96 g. of light yellow crystals for a total yield of 16.38 g. of the title A compound as a tannish solid; m.p. 87°-90° C. [α]D =-32.2° (c=1.15, methanol).

Quelle