Reaktion #3879

Reaktionsgleichung

N-methylmorpholine

t-butoxycarbonylphenylalanine

N-methylmorpholine

methyl 5-aminopentanoate hydrochloride

isobutylchloroformate

→

title compound

Ausbeute 96.2%

t-butoxycarbonyl-N-(5-methoxy-5-oxopentyl)-L-phenylalaninamide

Ausbeute 96.2%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter warming
2. 2
   Sonstigeat ca. -15°
3. 3
   Sonstigefor about ten minutes
4. 4
   Sonstigewas recooled to ca. -39°
5. 5
   SonstigeSolvent and other volatiles were removed by concentration in vacuo
6. 6
   SonstigeThe residue was triturated with ethyl acetate, which
7. 7
   Waschenwas then washed successively with water, 0.5M potassium bisulfate, water
8. 8
   Trocknenagain with 0.5M potassium bisulfate, and then dried over magnesium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated to a white solid
11. 11
    SonstigeAfter collection
12. 12
    Waschenthe white solid was washed thoroughly with Skellysolve B

Vorschrift

To a cold (ca -30° ), stirred solution of 26.5 g (0.1 mole) of t-butoxycarbonylphenylalanine (BOC-Phe) and 11.2 g (0.1 mole) of N-methylmorpholine in 150 ml of dimethylformamide (DMF) was added dropwise 13.2 ml (0.1 mole) of isobutylchloroformate. After warming and then holding the temperature at ca. -15° for about ten minutes, the solution was recooled to ca. -39°. To the cold mixture was added additional N-methylmorpholine (12.3 ml, ca. 0.11 mole), followed by 18.5 g (0.11 mole) of methyl 5-aminopentanoate hydrochloride. The mixture was allowed to warm to room temperature and to stand overnight. Solvent and other volatiles were removed by concentration in vacuo. The residue was triturated with ethyl acetate, which was then washed successively with water, 0.5M potassium bisulfate, water, and again with 0.5M potassium bisulfate, and then dried over magnesium sulfate, filtered, and concentrated to a white solid. After collection, the white solid was washed thoroughly with Skellysolve B to give 36.4 g of the title compound, m.p. 98°-100°. Recrystallization from ethyl acetate/Skellysolve B afforded analytically pure crystals.

Quelle