Acetic Acid → Benzoic acid, 4-(acetyloxy)-

HRID 2351788Notes

Reaction equation

[C:1]([O:4][C:5]1[CH:10]=[CH:9][C:8]([C:11](=[O:13])C)=[CH:7][CH:6]=1)(=[O:3])[CH3:2].C(OC(=O)C)(=[O:16])C.C(O)(=O)C.Br>[Ti]>[C:1]([O:4][C:5]1[CH:6]=[CH:7][C:8]([C:11]([OH:13])=[O:16])=[CH:9][CH:10]=1)(=[O:3])[CH3:2]

Participants

Conditions

Temperature: 300 fahrenheit

Procedure

One hundred and sixty-six (166) g (0.933 mole) of p-acetoxyacetophenone, 100 g (0.98 mole) of acetic anhydride, 250 g (4.17 moles) of acetic acid, 0.35 g (0.0014 mole) of Co(OAc)2.4H2O, 0.35 g (0.0014 mole) of Mn(OAc)2.4H2O, and 0.47 g (0.0028 mole) of 48% HBr were combined in a two-liter titanium-clad autoclave. The mixture was heated to 300° F. and pressurized to 300 psi. Air was introduced at a rate of 0.75 scf/min for 15 minutes and then lowered to 0.61 scf/min for the remainder of the reaction. During the run, a solution of 150 g (1.47 moles) of acetic anhydride and 38 g (0.63 mole) of acetic acid was added through a pump. The run time was 31 minutes. The reaction solution was concentrated by evaporating acetic acid from 696 g to 660 g. The precipitated p-acetoxybenzoic acid was isolated by filtration and dried to give 81.3 g of 97.6 mole % purity (47.2 mole % yield). Analysis of the filtrate showed: p-acetoxybenzoic acid, 32 mole %, p-hydroxybenzoic acid, 0.3 mole %, and p-acetoxyacetophenone, 3.2 mole %. Analysis of the reactor wash showed p-acetoxyacetophenone, 2.1 mole %. Total reaction yield of p-acetoxybenzoic acid was 81.3 mole %.

Workup

additionAir was introduced at a rate of 0.75 scf/min for 15 minutes
customlowered to 0.61 scf/min for the remainder of the reaction
concentrationThe reaction solution was concentrated
customby evaporating acetic acid from 696 g to 660 g

Sources & evidence

ORD record: ord-d50ce56e3bac46f1b7392593219805d8
Source dataset: uspto-grants-1989_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04873361

Reaction notes

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