Title: Coumalic Acid
CAS Registry Number: 500-05-0
CAS Name: 2-Oxo-1,2H-pyran-5-carboxylic acid
Additional Names: a-pyrone-5-carboxylic acid
Molecular Formula: C6H4O4
Molecular Weight: 140.09
Percent Composition: C 51.44%, H 2.88%, O 45.68%
Literature References: Prepd by heating anhydr malic acid with oleum: v. Pechmann, Ann. 264, 262, 272 (1891); Wiley, Smith, Org. Synth. coll. vol. IV, 201 (1963).
Properties: Bright yellow prisms from methanol, mp 205-210° (partial decompn). bp120 218°; sublimes partially. Sparingly sol in cold water. Dec by boiling water. Sol in alcohol, glacial acetic acid. Slightly sol in ether, acetone, ethyl acetate. Insol in chloroform, benzene, ligroin.
Melting point: mp 205-210° (partial decompn)
Boiling point: bp120 218°
Derivative Type: Methyl ester
Molecular Formula: C7H6O4
Molecular Weight: 154.12
Percent Composition: C 54.55%, H 3.92%, O 41.52%
Properties: Leaflets from ligroin, mp 73-74°. bp60 178-180°. bp760 250-260°.
Melting point: mp 73-74°
Boiling point: bp60 178-180°; bp760 250-260°
Derivative Type: Ethyl ester
Molecular Formula: C8H8O4
Molecular Weight: 168.15
Percent Composition: C 57.14%, H 4.80%, O 38.06%
Properties: Crystals, mp 36°. bp760 262-265°. Distills without decompn.
Melting point: mp 36°
Boiling point: bp760 262-265°
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