Hydrochloric Acid → 3-(Cyclopentyloxy)-4-methoxybenzoic acid

HRID 356910Notes

Reaction equation

[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:12]=[CH:13][C:14]=2[O:15][CH3:16])[CH:10]=[O:11])[CH2:5][CH2:4][CH2:3][CH2:2]1.C(=O)([O-])[O-:18].[Na+].[Na+].Cl.S(=O)(O)[O-].[Na+]>[Mn]([O-])(=O)(=O)=O.[K+]>[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:12]=[CH:13][C:14]=2[O:15][CH3:16])[C:10]([OH:18])=[O:11])[CH2:2][CH2:3][CH2:4][CH2:5]1

Participants

Conditions

Temperature: 50 °C

Procedure

A stirred saturated aqueous solution of potassium permanganate (100 mL) is treated with 3-cyclopentyloxy-4-methoxybenzaldehyde (7.4 g; that is prepared as described hereinbefore in Reference Example 1) and sodium carbonate (3.4 g) and the mixture is stirred at 50° C. for 1 hour, and then cooled to room temperature. The reaction mixture is acidified by treatment with concentrated hydrochloric acid and then it is treated with aqueous sodium bisulfite solution until a colorless solution is obtained. The reaction mixture is extracted with dichloromethane (2×100 mL) and the organic extracts are dried over magnesium sulfate and concentrated. The resulting residue is recrystallized from diethyl ether, to give 3-cyclopentyloxy-4-methoxybenzoic acid (4.78 g) in the form of white crystals. [NMR(CDCl3): 1.7(s,2H),1.8-2.2 (m,6H),3.95(s,3H),4.85(s,1H),6.9(bs,1H)7.6(bs,1H), 7.8(s,1H),9.8(s,1H); Elemental analysis: C,65.6; H,6.8%; Calculated: C,66.1; H,6.8%].

Workup

customthat is prepared
temperaturecooled to room temperature
customis obtained
extractionThe reaction mixture is extracted with dichloromethane (2×100 mL)
dry with materialthe organic extracts are dried over magnesium sulfate
concentrationconcentrated
customThe resulting residue is recrystallized from diethyl ether

Sources & evidence

ORD record: ord-3c97e48cdf954cb4b4d5334904a78356
Source dataset: uspto-grants-1998_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05840724

Reaction notes

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