Triethylamine → Ethyl 1,4-dibenzylpiperazine-2-carboxylate

反応式

Br[CH:2]([CH2:8]Br)[C:3]([O:5][CH2:6][CH3:7])=[O:4].[CH2:10]([NH:17][CH2:18][CH2:19][NH:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.C(N(CC)CC)C>C1(C)C=CC=CC=1>[CH2:10]([N:17]1[CH2:18][CH2:19][N:20]([CH2:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)[CH2:8][CH:2]1[C:3]([O:5][CH2:6][CH3:7])=[O:4])[C:11]1[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=1

参加物

反応条件

温度: 80 °C

実験手順

To a stirred solution of ethyl 2,3-dibromopropionate (142.7 g, 0.549 mol) in dry toluene (2000 mL) was added N,N′-dibenzylethylene diamine (132 g, 0.549 mol), followed by triethylamine (110.8 g, 1.098 mol), under N2 at 40° C. (a dense white precipitate formed immediately, thus good stirring was necessary). The mixture was heated at 80° C. overnight, cooled and filtered. The filtrate was then washed with H2O, dried over MgSO4, and concentrated under reduced pressure. The residue oil was taken on to the next step without further purification (GC-MS shows one peak at 6.79) or purified by column chromatography (EtOAc/hexane 1:4). Weight of crude product: 169.6 g (91%).