Reaktion #59219

Reaktionsgleichung

ninhydrin spray

N-acetyl-L-methionine

iodine

dicyclohexylcarbodiimide

N-t-butoxycarbonylpiperazine

→

1-(t-butoxycarbonyl) -4-(N-acetyl-L-methionyl)piperazine

Ausbeute 108.6%

Lösungsmittel

acetonitrile

CH2Cl2

acetonitrile

tetrahydrofuran

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe solvent was removed on a rotary evaporator
2. 2
   Filtrationfiltered
3. 3
   WaschenThe clear filtrate was washed
4. 4
   workup.ADDITIONwith dilute acid
5. 5
   workup.ADDITIONby dilute base
6. 6
   SonstigeThe organic layer was separated
7. 7
   Trocknendried over anhydrous sodium sulfate
8. 8
   Filtrationfiltered
9. 9
   Sonstigeevaporated

Vorschrift

A solution of 4.78 g (0.025 mol) of N-acetyl-L-methionine in CH2Cl2: acetonitrile (120 ml) was cooled to 0° C. To this solution was added 5.36 g (0.025 mol) of dicyclohexylcarbodiimide (DCC) followed by the rapid addition of 3.90 g (0.021 mol) of N-t-butoxycarbonylpiperazine in 6 ml of dichloromethane. The progress of the reaction was followed on silica gel TLC plates developed with 4:1 acetonitrile: tetrahydrofuran and visualized with either iodine or ninhydrin spray. The reaction was complete within 2 h. A few drops of glacial acetic acid were added to the reaction mixture and the solvent was removed on a rotary evaporator. The residue was taken up in ether and filtered. The clear filtrate was washed with dilute acid followed by dilute base. The organic layer was separated, dried over anhydrous sodium sulfate, filtered, and evaporated to give 8.2 g of 1-(t-butoxycarbonyl) -4-(N-acetyl-L-methionyl)piperazine, a colorless oil which required no further purification: IR (film) 3304, 3058, 2973, 2931, 2868, 1701, 1645, 1539, 1420, 1237, 1173 cm−1; NMR (CDCl3) δ 1.47 (s, 9 H), 1.80 (m, 2 H), 2.02 (s, 3 H), 2.10 (s, 3 H), 2.46 (m, 2 H), 3.53 (m, 8 H), 5.10 (M, 1 H), 6.35 (b, 0.5 H), 6.43 (b, 0.5 H).

Quelle