2-Hydroxy-p-toluic acid → Benzoic acid, 2-ethoxy-4-methyl-, ethyl ester

HRID 2120001Notes

Reaction equation

HRID 2120001 reaction equation
[CH2:1]([O:3][C:4]1[CH:5]=[C:6]([CH2:15]C(O)=O)[CH:7]=[CH:8][C:9]=1[C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH3:2].CC1C=C(O)C(=CC=1)C(O)=O.C(Br)C.S1(CCCC1)(=O)=O.C(=O)([O-])[O-].[K+].[K+].C(=O)([O-])[O-].[Na+].[Na+]>CN(C)C=O.CS(C)=O>[CH2:1]([O:3][C:4]1[CH:5]=[C:6]([CH3:15])[CH:7]=[CH:8][C:9]=1[C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH3:2]

Participants

9

Reactant 6

HCID 57882-Hydroxy-p-toluic acidHCID 6332Ethyl BromideHCID 10340Sodium CarbonateHCID 11430Potassium CarbonateHCID 31347SulfolaneHCID 101312123-Ethoxy-4-ethoxycarbonylphenylacetic acid

Product 1

HCID 11816602Benzoic acid, 2-ethoxy-4-methyl-, ethyl ester

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 6228DimethylformamideSolvent

Procedure

More particularly, the present invention relates to a process for the preparation of 3-ethoxy-4-(ethoxycarbonyl)phenyl acetic acid of Formula I, comprising reacting 4-methylsalicylic acid of Formula III, with ethylbromide in a dipolar aprotic solvent at a selected temperature within a range of ambient to 100° C., preferably 30-40° C. during a period of one to several hours. The suitable dipolar aprotic solvent is selected from the group consisting of dimethylsulphoxide, N, N-dimethyl formamide, sulfolane and N-methyl-1-pyrrolidone. The reaction is carried out in the presence of an inorganic base, preferably selected from the group consisting of potassium carbonate and sodium carbonate. The reaction is worked up following the conventional method to afford ethyl 2-ethoxy-4-methylbenzoate of Formula IV in practically quantitative yield. The compound of Formula IV is then reacted with lithium diisopropyl amide (LDA) of Formula VIII,

Sources & evidence

ORD record
ord-dd358747415b4122a021458a22ea778d
Source dataset
uspto-grants-2004_02
Patent number
US06686497B1

Reaction notes

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