Trifluoroacetic acid → (2E)-3-{4-[Cyclopentylidene(4-hydroxyphenyl)methyl]phenyl}-2-propenoic acid

HRID 229129Notes

Reaction equation

HRID 229129 reaction equation
[C:1]1(=[C:6]([C:22]2[CH:27]=[CH:26][C:25]([OH:28])=[CH:24][CH:23]=2)[C:7]2[CH:12]=[CH:11][C:10](/[CH:13]=[CH:14]/[C:15]([O:17]C(C)(C)C)=[O:16])=[CH:9][CH:8]=2)[CH2:5][CH2:4][CH2:3][CH2:2]1.FC(F)(F)C(O)=O>ClCCl>[C:1]1(=[C:6]([C:22]2[CH:27]=[CH:26][C:25]([OH:28])=[CH:24][CH:23]=2)[C:7]2[CH:12]=[CH:11][C:10](/[CH:13]=[CH:14]/[C:15]([OH:17])=[O:16])=[CH:9][CH:8]=2)[CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 689778841,1-Dimethylethyl (2E)-3-{4-[cyclopentylidene(4-hydroxyphenyl)methyl]phenyl}-2-propenoate

Product 1

HCID 11255664(2E)-3-{4-[Cyclopentylidene(4-hydroxyphenyl)methyl]phenyl}-2-propenoic acid

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To an ice-water cooled solution of 1,1-dimethylethyl (2E)-3-{4-[cyclopentylidene(4-hydroxyphenyl)methyl]phenyl}-2-propenoate (4) (0.28 g, 0.74 mmol) in dichloromethane (5 mL) was slowly added trifluoroacetic acid (5 mL) with stirring under a nitrogen atmosphere. After 1 h, the reaction mixture was concentrated in vacuo to give a solid. The solid was dissolved in dichloromethane and the solution was concentrated in vacuo to give a pale tan solid. The solid was triturated with diethyl ether and filtered to give the acrylic acid as an off-white solid. The solid was dried overnight under vacuum at 70° C., however, 1H NMR indicated that solvent remained in the sample. The solid was dissolved in methanol and the solution was concentrated in vacuo to give an oil. The oil was dissolved in methanol and the solution was concentrated in vacuo under high vacuum at 60° C. to give an oil. Dichloromethane was added to the oil and crystallization was induced with the aid of a spatula. The suspension was filtered and the solid was dried in a vacuum oven overnight at 70° C. to give 0.072 g (30%) of compound 5 as a yellow solid. 1H NMR (400 MHz, DMSO-d6): δ 1.60 (m, 4H), 2.30 (m, 4H), 6.44 (d, J=15.9 Hz, 1H), 6.67 (d, J=8.4 Hz, 2H), 6.90 (d, J=8.4 Hz, 2H), 7.13 (d, J=8.2 Hz, 2H), 7.53 (d, J=15.9 Hz, 1H), 7.57 (d, J=8.3 Hz, 2H), 9.32 (s, 1H). The compound was silated prior to EI analysis. HRMS (EI) Calcd for C27H36Si2O3: 464.2203 (M+.). Found: 464.2210.

Workup

  1. concentrationthe reaction mixture was concentrated in vacuo
  2. customto give a solid
  3. concentrationthe solution was concentrated in vacuo
  4. customto give a pale tan solid
  5. customThe solid was triturated with diethyl ether
  6. filtrationfiltered

Sources & evidence

ORD record
ord-b4f49289c530446e88b311a5dee73b54
Source dataset
uspto-grants-2009_07
Patent number
US07560589B2

Reaction notes

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