Sulfate Ion → 4'-(Heptyloxy)[1,1'-biphenyl]-4-carboxylic acid
Reaction equation
FC1(C2C(COC[C:20]3[C:25]([C:26]4(F)[C:32](F)=[C:31](O)[CH:30]=[CH:29][CH:27]4O)=[CH:24][CH:23]=[CH:22][CH:21]=3)=CC=CC=2)C(F)=C(O)C=CC1O.F[C:37]1[C:42](F)=[CH:41][CH:40]=[CH:39][C:38]=1[OH:44].S([O-])([O-])(=O)=O.CC[O:52][C:53](/N=N/C(OCC)=O)=[O:54].[CH:62]1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C(OCC)(=O)C(C)O>>[CH2:38]([O:44][C:30]1[CH:29]=[CH:27][C:26]([C:25]2[CH:20]=[CH:21][C:22]([C:53]([OH:54])=[O:52])=[CH:23][CH:24]=2)=[CH:32][CH:31]=1)[CH2:39][CH2:40][CH2:41][CH2:42][CH2:37][CH3:62]Participants
Procedure
2,3-Difluorohydroquinone monobenzyl ether (prepared from 2,3-difluorophenol by the Elbs reaction, benzylation of the sulfate obtained as an intermediate, and acid cleavage of the sulfate) is reacted with DEAD/PPh3 and optically active ethyl lactate. The protecting group is subsequently removed hydrogenolytically. At 0° C., 0.01 mol of the compound obtained in this way and 0.01 mol of 4'-heptyloxybiphenyl-4-carboxylic acid are reacted dropwise with 0.01 mol of DCC dissolved in methylene chloride, with exclusion of moisture in methylene chloride in the presence of a catalytic amount of DMAP [sic]. The mixture is stirred at room temperature for 12 hours, the dicyclohexylurea which precipitates is removed by filtration, and the filtrate is worked up in a customary manner. The product is purified by chromatography, to give ethyl 2-[2,3-difluoro-4-(p-(p-heptyloxyphenyl)benzoyloxy)phenoxy]propionate.
Workup
- customobtained as an intermediate
- customThe protecting group is subsequently removed hydrogenolytically
Sources & evidence
- ORD record
- ord-d066d10f8f714607ac028db2deba1497
- Source dataset
- uspto-grants-1993_08
- Patent number
- US05232624
Reaction notes
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