Squaric acid

Also known as: 1,2-DIHYDROXY-3,4-CYCLOBUTENEDIONE FOR S, 1-Cyclobutene-3,4-dione-1,2-diol, 1-Cyclobutene-3,4-dione-1,2-diol Squaric Acid, 2-dione, 3,4-DIHYDROXY-3-CYCLOBUTEN-1,2-DIONE, 3,4-DIHYDROXY-3-CYCLOBUTENE-1,2-DIONE, 3,4-DIHYDROXYCYCLOBUT-3-ENE-1,2-DIONE, 3,4-Dihydroxy-3-cyclobutene-1,2-dione, 3,4-Dihydroxycyclobut-3-en-1,2-dion, 3,4-Dihydroxycyclobut-3-ene-1,2-dione, 3-Cyclobutene-1,2-dione, 3,4-dihydroxy-, DIKETOCYCLOBUTENEDIOL, EINECS 220-761-4, MFCD00001334, NSC 624671, Quadratic acid, SQUARC ACID, SQUARICACIDDIBUTYLESTERS, Squaric, dihydroxy-cyclobutenedion

Squaric acid (CAS 2892-51-5) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C4H2O4 and a molecular weight of 114.056 g/mol. Key properties include a melting point of >300 °C(lit.), a boiling point of 251.0±50.0 °C at 760 mmHg, a density of 2.4±0.1 g/cm3 and a flash point of 119.8±26.6 °C. It is classified under GHS with signal word Warning and hazard statements H315 — Causes skin irritation, H317 — May cause an allergic skin reaction and H319 — Causes serious eye irritation. No supplier offers are currently listed; request a quote. Record last updated Nov 3, 2026.

CAS No.

2892-51-5

Jingsj CID

J-11536-6

Molecular Formula

C₄H₂O₄

Molecular Weight

114.056 g/mol

Category

Organic Acids

Last updated

11/3/2026