Reaktion #2254191

Reaktionsgleichung

Nε-Boc-Nα-Fmoc-L-lysine

DMF

cesium carbonate

4-methoxybenzyl chloride

→

Compound 2

Ausbeute 83.0%

2-Amino-6-tert-butoxycarbonylamino-hexanoic acid 4-methoxy-benzyl ester

Ausbeute 83.0%

Lösungsmittel

Hexane EtOAc

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturInto a 250 mL, flame
2. 2
   Sonstigedried three necked round bottom flask under nitrogen
3. 3
   Filtrationfiltered
4. 4
   Waschenwashed with ethyl acetate
5. 5
   SonstigeProduct isolation (EtOAc, 5% Na2CO3, water, Na2SO4) followed by recrystallization from 60/40 (v/v) hexane/EtOAc
6. 6
   Sonstigegave 2 crops of a colorless solid

Vorschrift

Compound 2 was prepared in two steps. Into a 250 mL, flame dried three necked round bottom flask under nitrogen was placed Nε-Boc-Nα-Fmoc-L-lysine (7.0 g, 15 mmol) and 60 mL of dry DMF. To this was added cesium carbonate (7 g, 21 mmol) and 4-methoxybenzyl chloride (2.5 g, 16 mmol). The suspension was stirred at room temperature under nitrogen for 4 h, then filtered and washed with ethyl acetate. Product isolation (EtOAc, 5% Na2CO3, water, Na2SO4) followed by recrystallization from 60/40 (v/v) hexane/EtOAc gave 2 crops of a colorless solid. mp 118-120° C. TLC Rf=0.33 (70/30 Hexane/EtOAc). Yield: 8.22 g, 14 mmol, 93.43%. 1H NMR(CDCl3) δ: 7.75 (d, J=7.2 Hz, 2H), 7.55 (d, J=7.2 Hz, 2H), 7.38 (t, J=7.5 Hz, 2H), 7.32-7.20 (m, 4H), 6.85-6.80 (m, 2H), 5.4 (d, J=7.6 Hz, 1H), 5.18-5.00 (m, 2H), 4.44-4.38 (m, 3H), 4.17 (t, J=6.0 Hz 1H), 3.80-3.70 (m, 4H), 3.00 (m, 2H), 1.90-1.11 (m, 15H). ESIMS m/z: 588.40 [M+1]+.

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