Z-Asn-OtBu → L-Asparagine tert-butyl ester
Reaction equation
[NH:1](C(OCC1C=CC=CC=1)=O)[C@H:2]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:3][C:4](=[O:6])[NH2:5]>C(OCC)(=O)C.[C].[Pd]>[NH2:1][C@H:2]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:3][C:4](=[O:6])[NH2:5]Participants
4
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
23.6 Grams (73.2 mmols) of Z-Asn-OtBu in 200 ml of ethyl acetate are hydrogenated in the presence of 2 g of palladium carbon (10% Pd) until, after 1 hour, hydrogen is no longer absorbed. The catalyst is filtered off and the filtrate concentrated, whereupon the product, melting at 96°-98° C., crystallizes out. Optical rotation [α]D20 =+2° (c=2.1 in methanol). In the thin-layer chromatogram on silica gel the Rf52 =0.30; Rf45 =0.50.
Workup
- customafter 1 hour
- customhydrogen is no longer absorbed
- filtrationThe catalyst is filtered off
- concentrationthe filtrate concentrated, whereupon the product, melting at 96°-98° C.
- customcrystallizes out
- customOptical rotation [α]D20 =+2° (c=2.1 in methanol)
Sources & evidence
- ORD record
- ord-f4f93f30d9f2472db0f1ff757226eea8
- Source dataset
- uspto-grants-1981_06
- Patent number
- US04271068
Reaction notes
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