Hydrochloric Acid → 4-(3-Chlorophenoxy)butanoic acid

Reaction equation

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

Participants

Reactant 4

HCID 313Hydrochloric Acid

HCID 7302Gamma-Butyrolactone

HCID 79333-Chlorophenol

HCID 14798Sodium Hydroxide

Product 1

HCID 30143424-(3-Chlorophenoxy)butanoic acid

Conditions

Temperature: 170 °C

Procedure

A dispersion was prepared by suspending 1 eq of NaOH (flakes) in 3-chlorophenol (1 eq). The obtained dispersion was heated to 170° C. up to complete solubilization of the base. 1.4 Eq. of γ-butyrolactone were then dropwise added maintaining the reaction mixture at 170° C. for 5 hours. The reaction mixture was then poured into ice and then acidified with HCl 6N. The reaction product was extracted with CHCl3, dehydrated over Na2SO4 and concentrated under vacuum. The residue was purified by flash chromatography (eluent oil ligroin/ethyl acetate 4:1 v/v) to obtain a yellow solid corresponding to 4-(3-chlorophenoxy)butyric acid. 27.96 mmoles of 4-(3-chlorophenoxy)butyric acid were added to 48 grams of polyphosphoric acid and the resulting mixture was maintained under stirring at 90° C. for 2 hours. At the end the reaction mixture was then poured on ice and extracted with CH2Cl2. The pooled organic phases were washed with a 10% Na2CO2 aqueous solution, dehydrated over Na2SO4, and concentrated under vacuum. The residue was purified by flash chromatography (oil ligroin/ethyl acetate 9/1 v/v). An orange oil corresponding to 8-chloro-1-oxo-2,3,4,5-tetrahydrobenzo-cycloheptan-5-one was obtained.