Trifluoroacetic acid → methyl D-isoglutaminate trifluoroacetic acid salt
Reaction equation
C(OC([NH:8][C@@H:9]([C:16](=[O:18])[NH2:17])[CH2:10][CH2:11][C:12]([O:14][CH3:15])=[O:13])=O)(C)(C)C.[F:19][C:20]([F:25])([F:24])[C:21]([OH:23])=[O:22]>>[F:19][C:20]([F:25])([F:24])[C:21]([OH:23])=[O:22].[NH2:8][C@@H:9]([C:16](=[O:18])[NH2:17])[CH2:10][CH2:11][C:12]([O:14][CH3:15])=[O:13]Participants
Procedure
Methyl t-butyloxycarbonyl-D-isoglutaminate (651 mg, 2.5 mmol) was treated with cold trifluoroacetic acid (5 ml) in a similar manner to that described in Example 33 (IV) to obtain methyl D-isoglutaminate trifluoroacetic acid salt. This salt was then dissolved in ethyl acetate (5 ml), and neutralized by adding TEA (0.35 ml) with cooling. To the resulting solution was added a solution of t-butyloxycarbonyl-O-benzyl-L-serine HONB active ester in ethyl acetate (5 ml), and the reaction was carried out at room temperature for 16 hours. The work-up similar to that described in Example 33 (I) and recrystallization from ethyl acetate/ether gave methyl t-butyloxycarbonyl-O-benzyl-L-seryl-D-isoglutaminate (0.78 g). m.p. 103°-104° C. [α]D22 +7.0 (C 0.5, ethanol). Rf5 =0.40.
Sources & evidence
- ORD record
- ord-e95bdc292cfe4f3a8f09458681b03120
- Source dataset
- uspto-grants-1983_01
- Patent number
- US04369178
Reaction notes
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