Dicyclohexylcarbodiimide → Z-Ser(tBu)-Asn-Leu-OMe

HRID 1076412Notes

Reaction equation

[NH2:1][C@H:2]([C:7]([NH:9][C@H:10]([C:15]([O:17][CH3:18])=[O:16])[CH2:11][CH:12]([CH3:14])[CH3:13])=[O:8])[CH2:3][C:4](=[O:6])[NH2:5].[NH:19]([C:30]([O:32][CH2:33][C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1)=[O:31])[C@H:20]([C:27](O)=[O:28])[CH2:21][O:22][C:23]([CH3:26])([CH3:25])[CH3:24].ON1C(=O)CCC1=O.C1(N=C=NC2CCCCC2)CCCCC1>CN(C)C=O>[NH:19]([C:30]([O:32][CH2:33][C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1)=[O:31])[C@H:20]([C:27]([NH:1][C@H:2]([C:7]([NH:9][C@H:10]([C:15]([O:17][CH3:18])=[O:16])[CH2:11][CH:12]([CH3:14])[CH3:13])=[O:8])[CH2:3][C:4](=[O:6])[NH2:5])=[O:28])[CH2:21][O:22][C:23]([CH3:24])([CH3:26])[CH3:25]

Participants

Conditions

Temperature: 0 °C

Procedure

8.90 g of H-Asn-Leu-OMe and 11.0 g of Z-Ser(tBu)-OH are dissolved in 100 ml of freshly distilled dimethylformamide. The solution is cooled to 0°C and 3.90 g of N-hydroxysuccinimide followed by 8.70 g of dicyclohexylcarbodiimide are added. After 30 minutes standing at 0°C and 18 hours at 25°C the precipitated dicyclohexylurea is filtered off and the filtrate is poured into 800 ml of ice water. The crystalline precipitate which hereupon separates out is dried in vacuo at 40°C and then recrystallised from methanol-water. The Z-Ser(tBu)-Asn-Leu-OMe which is hereupon obtained in an analytically pure form melts at melting point 202° - 205°C; [α]D20 =-18° (c = 1.05 in glacial acetic acid).

Workup

additionare added
filtrationthe precipitated dicyclohexylurea is filtered off
additionthe filtrate is poured into 800 ml of ice water
customThe crystalline precipitate which hereupon separates out is dried in vacuo at 40°C
customrecrystallised from methanol-water

Sources & evidence

ORD record: ord-c70ae3c6a709420d9fc218f19fd2a7bc
Source dataset: uspto-grants-1976_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US03956260

Reaction notes

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