1-Hydroxybenzotriazole → Fmoc-leucine

HRID 1196731Notes

Reaction equation

HRID 1196731 reaction equation
[NH:1]([C:10]([O:12][CH2:13][CH:14]1[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[C:20]2[C:15]1=[CH:16][CH:17]=[CH:18][CH:19]=2)=[O:11])[C@H:2]([C:7]([OH:9])=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5].N1CCCCC1.CN(C=O)C.[NH:38]([C:57]([O:59][CH2:60][CH:61]1[C:73]2[C:68](=[CH:69][CH:70]=[CH:71][CH:72]=2)[C:67]2[C:62]1=[CH:63][CH:64]=[CH:65][CH:66]=2)=[O:58])[C@@H:39]([C:43](OC1C(F)=C(F)C(F)=C(F)C=1F)=[O:44])[CH:40]([CH3:42])[CH3:41].C1C=CC2N(O)N=NC=2C=1>CN(C=O)C.O>[NH:1]([C:10]([O:12][CH2:13][CH:14]1[C:15]2[C:20](=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:21]2[C:26]1=[CH:25][CH:24]=[CH:23][CH:22]=2)=[O:11])[C@H:2]([C:7]([OH:9])=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5].[NH:38]([C:57]([O:59][CH2:60][CH:61]1[C:62]2[C:67](=[CH:66][CH:65]=[CH:64][CH:63]=2)[C:68]2[C:73]1=[CH:72][CH:71]=[CH:70][CH:69]=2)=[O:58])[C@@H:39]([C:43]([NH:1][C@H:2]([C:7]([OH:9])=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5])=[O:44])[CH:40]([CH3:42])[CH3:41]

Participants

8

Reactant 4

HCID 757711-HydroxybenzotriazoleHCID 1549133Fmoc-leucineHCID 23501187piperidine N,N-dimethylformamideHCID 53229919D-Valine, N-[(9H-fluoren-9-ylmethoxy)carbonyl]-, pentafluorophenyl ester

Product 2

HCID 1549133Fmoc-leucineHCID 131717383HCID 131717383, compound

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent4×

Procedure

Fmoc-Leu-resin(0.093 mmol/g, 1.0 g) which was prepared from ULTROSYN B(Pharmacia LKB Biotechnology) and Fmoc-Leu by a symmetrical acid anhydride method, was previously swelled in DMF, and packed in a reaction column of a BIOLYNX 4175 peptide synthesizer(Pharmacia LKB Biotechnology) and a solid phase peptide synthesis was performed manually by the standard protocol; 20% piperidine/DMF was pumped through the reaction column for 10 min(flow rate: 3.5 ml/min) to deprotect Fmoc group. Then DMF was pumped for 10 min(3.5 ml/min) to remove excess base. Each 2.5 equivalents of Fmoc-DVal-OPfp and HOBT.H2O was dissolved in DMF(1 ml). The solution was drawn into the reaction system and recirculated for 1 h(3.5 ml/min) to achieve acylation of the amino groups present on the resin. DMF was pumped for 5 min (3.5 ml/min) to wash excess reagents out, to give Fmoc-DVal-Leu-resin. In a similar manner, Fmoc-Lys(Boc)-OPfp, Fmoc-DAsp(OtBu) and Fmoc-DTrp-OPfp were successively coupled with the corresponding resin bound peptide. In the case of the coupling reaction of DAsp, were used each 5 equivalents of Fmoc-DAsp(OtBu) and HOBT.H2O, and 4 equivalents of DIPC. Completion of each acylation reaction was judged by the Kaiser test [Anal. Biochem., 34, 595(1970)]. If the acylation reaction was imcomplete, additional recirculation was performed until the Kaiser test turned negative. Finally the Fmoc group of the resin bound pentapeptide was deprotected in a reaction column by pumping 20% piperidine/DMF for 10 min(3.5 ml/min). The resin was unpacked from a reaction column, washed on a glass filter successively with DMF, tert-amyl alcohol, acetic acid, tert-amyl alcohol, DMF and ether, and dried in vacuo to give DTrp-DAsp(OtBu)-Lys(Boc)-DVal-Leu-resin (1.06 g). 10% Hydradine monohydrate/1,4-dioxane/methanol(v/v, 9/1, 3.0 ml) was added to the resin and the mixture was allowed to stand at room temperature for 2 h with occasional shaking. The resin was filtered out and washed several times with each small amount of 1,4-dioxane/methanol(9/1). The combined filtrate and washings were neutralized with dry ice and concentrated in vacuo. Water(10 ml) was added to the residue to precipitate a solid, which was collected by filtration and dried in vacuo to give DTrp-DAsp(OtBu)-Lys(Boc) -DVal-Leu-NHNH,(65.3 mg) as a colorless powder.

Workup

  1. custom(3.5 ml/min) to remove excess base
  2. wash(3.5 ml/min) to wash excess reagents out

Sources & evidence

ORD record
ord-81c8b3062ad94ddb9a4d5dc9eba7dacb
Source dataset
uspto-grants-1992_05
Patent number
US05114918

Reaction notes

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