Synthesis of terephthalic acid

Preparation of terephthalic acid

Preparation of terephthalic acid

Preparation of terephthalic acid

10 g of pure p-xylene are boiled under reflux condenser with a mixture of 40 g potassium bichromate (or sodium bichromate), 30 ml concentrated sulfuric acid, and 60 ml water. The solution gradually acquires a green colour, and the terephthalic acid separates out, especially on the sides of the flask, as a slightly colored, incoherent mass. After 15 hours the unreacted p-xylene is distilled off in steam, and the cooled solution is filtered. To purify the raw terephthalic acid which has separated, it is dissolved in a warm, dilute solution of sodium carbonate, and precipitated again from the filtrate by means of hydrochloric acid. The yield of terephthalic acid is 4 g. Terephthalic acid is extremely slightly solubilble in water, alcohol, and ether.

Introduction to the preparation of organic compounds, E. Fisher, 81, 1909

Preparation of terephthalic acid

Preparation of terephthalic acid

10 g of p-toluic acid dissolved in 600 ml of 1% sodium hydroxide solution are refluxed on a water bath, and 5% aqueous potassium permanganate solution added until the red colour of the permanganate solution persists on boiling; for this about 500 ml of potassium permanganate solution will be required. Excess of potassium permanganate is destroyed either by adding alcohol until the liquid is colourless, the alcohol being oxidised to acetaldehyde or acetic acid, or sulphur dioxide is bubbled through the warm solution until all the manganese dioxide precipitated during the reaction dissolves. Terephthalic acid is then precipitated after filtering off the manganese dioxide by addition of conc. hydrochloric acid at the boiling point, in the latter terephthalic acid is precipitated by the sulphur dioxide during the removal of excess permanganate. In both, the acid is filtered from the cooled reaction mixture, well washed with cold water, and dried on a water bath. It is purified by reprecipitation with acid from an alkaline solution. Yield 90% as colourless crystals; insoluble in water and in alcohol; sublimes without melting at 300° C.

Systematic organic chemistry, by W. M. Cumming, 247, 1937.


terephthalic acid



InChI Key


Canonical SMILES


MeSH Synonyms

disodium terephthalate, terephthalate, terephthalic acid

Depositor-Supplied Synonyms

TEREPHTHALIC ACID, p-Phthalic acid, 100-21-0, 1,4-Benzenedicarboxylic acid, p-Dicarboxybenzene, p-Benzenedicarboxylic acid, benzene-1,4-dicarboxylic acid, p-Carboxybenzoic acid, Acide terephtalique, para-Phthalic acid, Tephthol, WR 16262, Kyselina terftalova, NSC 36973, Kyselina tereftalova, TA-33MP, 1,4-dicarboxybenzene, TA 12, Benzene-p-dicarboxylic acid, Acide terephtalique [French], Kyselina tereftalova [Czech], CCRIS 2786, HSDB 834, CHEBI:15702, KKEYFWRCBNTPAC-UHFFFAOYSA-N, EINECS 202-830-0, SBB060285, BRN 1909333, AI3-16108, DSSTox_CID_6080, DSSTox_RID_78007, DSSTox_GSID_26080, CAS-100-21-0, p-Phthalate, terephtalic acid, P-Phthelate, P-Phthelic acid, p-Benzenedicarboxylate, terephthalsäure, 4-Carboxybenzoic Acid, Amoco TA 33, Benzene-p-dicarboxylate, ACMC-1BUZR, S-LOP, AC1L1OVJ, benzene-1,4-dioic acid, WLN: QVR DVQ, UNII-6S7NKZ40BQ, SCHEMBL1655, para-benzenedicarboxylic acid, 6S7NKZ40BQ, Benzene, p-dicarboxylic acid, TA 33LP, KSC176K6T, BIDD:ER0245, 185361_ALDRICH, CHEMBL1374420, Benzene, 1,4-Dicarboxylic acid, CTK0H6569, HMDB02428, MolPort-001-781-626, NSC36973, Tox21_201659, Tox21_303229, ANW-14186, LS-297, NSC-36973, RW2132, STL281856, AKOS000119464, MCULE-9289682931, NE10209, NCGC00091618-01, NCGC00091618-02, NCGC00091618-03, NCGC00257014-01, NCGC00259208-01, AJ-61314, AK137962, AN-24546, BP-21157, KB-10500, KB-60718, OR033999, OR192263, AB1002532, RT-000438, ST2407586, FT-0674866, ST50824887, 6806-EP2270113A1, 6806-EP2272935A1, 6806-EP2284165A1, 6806-EP2292611A1, 6806-EP2298776A1, 6806-EP2301536A1, 6806-EP2301538A1, 6806-EP2305808A1, 6806-EP2308865A1, 6806-EP2311455A1, 6806-EP2314295A1, 6806-EP2314575A1, 6806-EP2374895A1, C06337, 4-09-00-03301 (Beilstein Handbook Reference), AE-562/40217759, 3B4-0144, I01-7746, 3B1-000700, 211863-90-0, 211863-92-2, QTA

Removed Synonyms

Terephthalate, Disodium terephthalate, 1,4-Benzenedicarboxylate, CID7489, T0166, C011363, TPA, 5372-81-6, 636-94-2, PTA

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