Reaktion #450581

Reaktionsgleichung

N-(diphenylmethylene)-glycine ethyl ester

1-bromooctadecane

lithium bis(trimethylsilyl)amide

→

off-white crystalline solid

Ausbeute 80.0%

Ethyl N-(diphenylmethylene)-2-aminoeicosanoate

Ausbeute 80.0%

Lösungsmittel

DMPU

THF

DMPU

THF

ethyl acetate

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturWhile maintaining the temperature at -78° C.
2. 2
   workup.ADDITIONwas added over a 10 min period
3. 3
   Temperaturto warm to room temperature
4. 4
   workup.STIRRINGAfter stirring the mixture for 17 h
5. 5
   WaschenThe solution was washed with H2O (4×2 l)
6. 6
   TrocknenThe solution was dried over Na2CO3 -Na2SO4
7. 7
   SonstigeThe product was crystallized by the addition of hexane

Vorschrift

To a stirred solution of N-(diphenylmethylene)-glycine ethyl ester (67.3 g, 0.250 mol) in a 1:1 mixture of anhydrous THF (500 ml) and DMPU (500 ml) at -78° C. under a dry argon atmosphere was added a solution of lithium bis(trimethylsilyl)amide (250 ml--1.0M in THF, 0.25 mol) over a 10 min period. The resulting orange solution was stirred for 1.5 h at -78° C. While maintaining the temperature at -78° C., a solution of 1-bromooctadecane (83.4 g, 0.250 mol) in a 1:1 mixture of anhydrous THF (250 ml) and DMPU (250 ml) was added over a 10 min period and the resulting mixture was allowed to warm to room temperature. After stirring the mixture for 17 h, H2O (50 ml) and then ethyl acetate (2 l) were added. The solution was washed with H2O (4×2 l). The solution was dried over Na2CO3 -Na2SO4 and the volume was reduced in vacuo to 1 l. The product was crystallized by the addition of hexane to give 104 g (80% yield) of an off-white crystalline solid: mp 62°-5° C.; 1H NMR (CDCl3) δ 0.88 (t, J =6.6 Hz, 3 H), 1.27 (m, 35 H), 1.90 (m, 2 H), 4.03 (m, 1 H), 4.17 (m, 2 H), 7.17 (m, 2 H), 7.36 (m, 6 H), 7.64 (m, 2 H).

Quelle