Dimethylformamide → HCID 178454171, compound
Reaction equation
[NH:1]([C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])[C@H:2]([C:16]([OH:18])=[O:17])[CH2:3][C:4]1[N:8]=[CH:7][N:6](C(OC(C)(C)C)=O)[CH:5]=1.C1CCC(N=C=N[CH:35]2[CH2:40][CH2:39]CCC2)CC1.[CH3:41]N(C=O)C.[C:46]([O:49]CC)(=[O:48])C>>[C:46]([O:18][C:16](=[O:17])[C@H:2]([CH2:3][C:4]1[N:8]=[CH:7][NH:6][CH:5]=1)[NH:1][C:19]([O:21][C:22]([CH3:23])([CH3:24])[CH3:25])=[O:20])([O:49][C:40]([CH3:39])([CH3:35])[CH3:41])=[O:48]Participants
Procedure
A mixture of Boc-His(Boc)-OH (506 mg, 1.42 mmol), Compound I-5 (418 mg, 0.92 mmol) and DCC (195 mg, 0.96 mmol) in CE2Cl2 /DMF (1:1, 2.4 mL) was stirred 12 hours at ambient temperature. The reaction mixture was diluted with ethyl acetate (25 mL) and filtered. The ethyl acetate layer was washed with a 2% NaHCO3 solution (2×20 mL), saturated NaCl solution (1×20 mL) and dried (MgSO4). Petroleum ether was added and a yellowish-green precipitate was collected. Purification by column chromatography (silica gel; EtOAc; Rf=0.4) gave 154 mg, (38%) of the Boc-Histidine(Boc) ester as a white solid. 1H NMR (DMSO-d6) δ 1.35 (s, 9H, tBu), 1.48 (s, 9H, tBu). A solution of the product from Example-9 step-1 (144 mg) in EtOAc (2 mL) was added 4N mL). The mixture was stirred for 2 h at room temperature, diluted with water (30 mL) and extracted with EtOAc (1×30 mL) and ether (1×30 mL). The aqueous layer was lyophilized to give a solid product ester (105 mg, 86%), mp 228° C. (dec.), MS m/z=592 (M+1)+.
Workup
- filtrationfiltered
- washThe ethyl acetate layer was washed with a 2% NaHCO3 solution (2×20 mL), saturated NaCl solution (1×20 mL)
- dry with materialdried (MgSO4)
- additionPetroleum ether was added
- customa yellowish-green precipitate was collected
- customPurification by column chromatography (silica gel; EtOAc; Rf=0.4)
Sources & evidence
- ORD record
- ord-0e224ec522dd489094eb7e13a51b04c7
- Source dataset
- uspto-grants-1997_07
- Patent number
- US05650407
Reaction notes
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