N,N'-Dicyclohexylurea → Z-Ser(tBu)-Asn-Leu-OMe

HRID 1679833Notes

Reaction equation

HRID 1679833 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.C(NC1CCCCC1)(NC1CCCCC1)=O>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

7

Reactant 5

HCID 4277N,N'-DicyclohexylureaHCID 10868DicyclohexylcarbodiimideHCID 80170N-HydroxysuccinimideHCID 1715617Z-Ser(tBu)-OHHCID 57097841H-Asn-Leu-OMe

Product 1

HCID 131710201Z-Ser(tBu)-Asn-Leu-OMe

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A solution of 8.90 g of H-Asn-Leu-OMe and 11.0 g of Z-Ser(tBu)-OH in 100 ml of freshly distilled dimethylformamide is cooled to 0° C. and mixed with 3.90 g of N-hydroxysuccinimide and 8.70 g of dicyclohexyl carbodiimide. After allowing the batch to stand for 30 minutes at 0° C. and then for 18 hours at 25° C. the precipitated dicyclohexylurea is suctioned off and the filtrate poured into 800 ml of ice water. The resulting crystalline precipitate is dried under vacuum at 40° C. and then recrystallized from aqueous methanol. The resulting analytically pure product - Z-Ser(tBu)-Asn-Leu-OMe -melts at 202°-205° C. Optical rotation [α]D20 =18° (c=1.05 in glacial acetic acid).

Workup

  1. customThe resulting crystalline precipitate is dried under vacuum at 40° C.
  2. customrecrystallized from aqueous methanol
  3. customOptical rotation [α]D20 =18° (c=1.05 in glacial acetic acid)

Sources & evidence

ORD record
ord-fd9ac1a0a1df4c46bcbf2e84bc70f546
Source dataset
uspto-grants-1981_06
Patent number
US04271068

Reaction notes

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