Formaldehyde → 1,3-Dihydro-1-oxoisobenzofuran-5-carboxylic acid

HRID 2180314Notes

Reaction equation

[C:1]([OH:12])(=[O:11])[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1.[CH2:13]=O>>[C:6]([C:5]1[CH:9]=[C:10]2[C:2](=[CH:3][CH:4]=1)[C:1](=[O:12])[O:11][CH2:13]2)([OH:8])=[O:7]

Participants

Reactant 2

HCID 712Formaldehyde

HCID 7489Terephthalic Acid

Product 1

HCID 785171,3-Dihydro-1-oxoisobenzofuran-5-carboxylic acid

Procedure

In the method of the invention, the terephthalic acid is condensed with paraformaldehyde liberating water, which reacts with the SO3. When the reaction is complete, 5-carboxyphthalide may be isolated as follows. The reaction mixture is hydrolysed with water. The condensed product, 5-carboxyphthalide inclusive possible diphthalide impurities may then be filtered off, and the 5-carboxyphthalide may be dissolved in aqueous medium by adjusting pH to about 6.7 to 7.3, leaving possible diphthalide impurities in the solid phase The diphthalide present may be filtered off whereupon 5-carboxyphthalide may be precipitated by acidification, filtered off, washed with water and dried.

Workup

customreacts with the SO3

Sources & evidence

ORD record: ord-33797d5b84e545db87aa310674f003b2
Source dataset: uspto-grants-2005_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06888009B2

Reaction notes

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