Trifluoroacetic acid → 2-[2,4-Bis(benzyloxy)phenyl]acetic Acid
Reaction equation
F[C:2](F)(F)[C:3]([OH:5])=[O:4].[N+]([C:11]1[CH:16]=[CH:15][C:14]([O:17][C:18](=O)[C@H:19]([CH2:21][C:22](=O)N)N)=[CH:13][CH:12]=1)([O-])=O.[N+](C1C=CC(OC(=O)[C@H](CC(=O)N)NC([O:41][CH2:42][C:43]2[CH:48]=[CH:47][C:46](OC)=[CH:45][CH:44]=2)=O)=CC=1)([O-])=O.FC(F)(F)C(O)=O.[C:63]1(OC)[CH:68]=CC=C[CH:64]=1>CN(C)C=O>[CH2:18]([O:17][C:14]1[CH:13]=[C:12]([O:41][CH2:42][C:43]2[CH:48]=[CH:47][CH:46]=[CH:45][CH:44]=2)[CH:11]=[CH:16][C:15]=1[CH2:2][C:3]([OH:5])=[O:4])[C:19]1[CH:21]=[CH:22][CH:68]=[CH:63][CH:64]=1Participants
Procedure
The above obtained crude 2,4-dibenzyloxyphenylacetyl chloride [X] was dissolved in anhydrous N,N-dimethylformamide (20 ml) and then thereto was added a solution of L-asparagine p-nitrophenyl ester trifluoroacetate in anhydrous N,N-dimethylformamide [prepared by treating N-(p-methoxybenzyloxycarbonyl)-L-asparagine p-nitrophenyl ester (1.6 g) with trifluoroacetic acid (3 ml) in the presence of anisole (1.2 g) at 0° C. for 1 hour, concentrating the treated product to dryness under reduced pressure and dissolving the residue in anhydrous N,N-dimethylformamide (20 ml)]. Thereto was further added triethylamine (1.8 ml), followed by concentrating under reduced pressure at 40° C. or lower. The residue was subjected to separation and purification by a silica gel column (inner diameter: 5 cm, length: 30 cm; developer: ethyl acetate) to obtain 2,4-dibenzyloxyphenylacetyl-L-asparagine p-nitrophenyl ester [IIa-1] (290 mg, yield from [IX] 13%).
Workup
- customprepared
- concentrationconcentrating the treated product to dryness under reduced pressure
- dissolutiondissolving the residue in anhydrous N,N-dimethylformamide (20 ml)]
- concentrationby concentrating under reduced pressure at 40° C.
- customThe residue was subjected to separation and purification by a silica gel column (inner diameter: 5 cm, length: 30 cm; developer: ethyl acetate)
Sources & evidence
- ORD record
- ord-a9145d07242d45faac07c29aaab9d6f9
- Source dataset
- uspto-grants-1990_04
- Patent number
- US04918107
Reaction notes
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