Tyrosine Methyl Ester → HCID 131721855, compound
Reaction equation
[NH2:1][C@H:2]([C:11]([O:13][CH3:14])=[O:12])[CH2:3][C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][CH:5]=1.[NH:15]([C:23]([O:25][C:26]([C:29]1[CH:38]=[C:35]([O:36][CH3:37])[CH:34]=[C:31]([O:32][CH3:33])[CH:30]=1)([CH3:28])[CH3:27])=[O:24])[C@H:16]([C:20](O)=[O:21])[CH:17]([CH3:19])[CH3:18].C1C=C2C(N(O)N=NC2=CC=1)=O>CN(C=O)C>[NH:15]([C:23]([O:25][C:26]([C:29]1[CH:30]=[C:31]([O:32][CH3:33])[CH:34]=[C:35]([O:36][CH3:37])[CH:38]=1)([CH3:28])[CH3:27])=[O:24])[C@@H:16]([C:20]([NH:1][C@H:2]([C:11]([O:13][CH3:14])=[O:12])[CH2:3][C:4]1[CH:5]=[CH:6][C:7]([OH:10])=[CH:8][CH:9]=1)=[O:21])[CH:17]([CH3:18])[CH3:19]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Solution Phase Couplings with Ddz-Xxx-Pfp and Ddz-Xxx-ODhbt. The efficiency of acylation of ODhbt esters, in terms of both coupling and racemization, was examined through the acylation of a simple amino acid alkyl ester, i.e., the acylation of H-Tyr-OMe with Ddz-L-Val-Dhbt and Ddz-D-Val-ODhbt in DMF at 0.1M. The dipeptides Ddz-L-Val-Tyr-OMe and Ddz-D-Val-Tyr-OMe were obtained in high yield (>90%) after a simple extractive workup and the Ddz-L-Val-Tyr-OMe gave a clean, single peak HPLC trace. Ddz-D-Val-ODhbt was not obtained as a solid, as it was contaminated with 5% of the azidobenzoate impurity, as mentioned by Atherton, et al.,54 which showed up in the HPLC trace. Both dipeptides gave clean 1H-NMR spectra. The attempted separation of the diastereomeric dipeptides by HPLC was unsuccessful over a wide range of isocratic gradients. In the 1H-NMR spectra, however, there is a slight difference in shift of the Val α-CH between the two dipeptides, hence there is no evidence in either spectra of any measurable amount of racemization.
Sources & evidence
- ORD record
- ord-88254b85ab4249369e07d6c2f4b396a3
- Source dataset
- uspto-grants-2000_06
- Patent number
- US06075141
Reaction notes
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