Lithium Hexamethyldisilazide → 4-[2-(2-Benzyloxyphenyl)-(E)-ethenyl]-2-hydroxybenzoic acid

HRID 2395017Notes

Reaction equation

HRID 2395017 reaction equation
C(OC1C=C(C)C=CC=1C(OC)=O)(=O)C.[CH2:16]([O:23][C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][C:25]=1/[CH:30]=[CH:31]/[C:32]1[CH:41]=[CH:40][C:35]([C:36]([O:38]C)=[O:37])=[C:34]([OH:42])[CH:33]=1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.C(OC1C=CC=CC=1/C=C\C1C=CC(C(OC)=O)=C(O)C=1)C1C=CC=CC=1.C(OC1C=CC=CC=1C=CC1C=CC(C(OC)=O)=CC=1F)C1C=CC=CC=1.FC1C=C(C=CC=1C)C(OC)=O.C[Si](C)(C)[N-][Si](C)(C)C.[Li+]>>[CH2:16]([O:23][C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][C:25]=1/[CH:30]=[CH:31]/[C:32]1[CH:41]=[CH:40][C:35]([C:36]([OH:38])=[O:37])=[C:34]([OH:42])[CH:33]=1)[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1

Participants

7

Reactant 6

HCID 2733832Lithium HexamethyldisilazideHCID 18973756methyl 4-[2-(2-benzyloxyphenyl)-(E)-ethenyl]-2-hydroxybenzoateHCID 18973767Methyl 3-fluoro-4-methylbenzoateHCID 21841044Methyl 2-acetoxy-4-methylbenzoateHCID 54449624Methyl 4-[2-(2-benzyloxyphenyl)ethenyl)-3-fluorobenzoateHCID 70346139methyl 4-[2-(2-benzyloxyphenyl)-(Z)-ethenyl]-2-hydroxybenzoate

Product 1

HCID 189737864-[2-(2-Benzyloxyphenyl)-(E)-ethenyl]-2-hydroxybenzoic acid

Procedure

Methyl 2-acetoxy-4-methylbenzoate was converted to a mixture of methyl 4-[2-(2-benzyloxyphenyl)-(E)-ethenyl]-2-hydroxybenzoate and methyl 4-[2-(2-benzyloxyphenyl)-(Z)-ethenyl]-2-hydroxybenzoate using the procedures described in Example 8 for the synthesis of methyl 4-[2-(2-benzyloxyphenyl)ethenyl)-3-fluorobenzoate from methyl 3-fluoro-4-methylbenzoate (using 2 equivalents of lithium hexamethyldisilazide in the final step). The isomers were separated by subjecting to chromatography on silica gel using a dichloromethane:hexane (1:2) as eluant. Further purification of the isomers was achieved by crystallisation.

Workup

  1. customThe isomers were separated
  2. customFurther purification of the isomers
  3. customwas achieved by crystallisation

Sources & evidence

ORD record
ord-d718f0b7e4234148bcc18cec5fc578ce
Source dataset
uspto-grants-1998_09
Patent number
US05811459

Reaction notes

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