The CAS registry number of 4H-1-Benzopyran-2-carboxylicacid, 4-oxo- is 4940-39-0. Its EINECS registry number is 225-583-0. The IUPAC name is 4-oxochromene-2-carboxylic acid. In addition, the molecular formula is C₁₀H₆O₄ and the molecular weight is 190.15. It is also called 2-chromonecarboxylic acid. What's more, it is a kind of white to light yellow crystal powder and belongs to the classes of Aromatic Carboxylic Acids, Amides, Anilides, Anhydrides & Salts. And it should be stored in a cool and dry place.

Physical properties about this chemical are: (1)ACD/LogP: 1.65; (2)ACD/LogD (pH 5.5): -1.46; (3)ACD/LogD (pH 7.4): -2.09; (4)ACD/BCF (pH 5.5): 1; (5)ACD/BCF (pH 7.4): 1; (6)ACD/KOC (pH 5.5): 1; (7)ACD/KOC (pH 7.4): 1; (8)#H bond acceptors: 4; (9)#H bond donors: 1; (10)#Freely Rotating Bonds: 1; (11)Polar Surface Area: 52.6 Å²; (12)Index of Refraction: 1.639; (13)Molar Refractivity: 45.86 cm³; (14)Molar Volume: 127.3 cm³; (15)Polarizability: 18.18 ×10^-24cm³; (16)Surface Tension: 66.8 dyne/cm; (17)Density: 1.493 g/cm³; (18)Flash Point: 138.9 °C; (19)Enthalpy of Vaporization: 61.24 kJ/mol; (20)Boiling Point: 337 °C at 760 mmHg; (21)Vapour Pressure: 4.23E-05 mmHg at 25°C.

Preparation of 4H-1-Benzopyran-2-carboxylicacid, 4-oxo-: it can be prepared by 1-methyl-1-(4-oxochromen-2-yl)ethyl 4-oxochromen-2-carboxylate. The other product is 2-(1-methylvinyl)chromen-4-one. This reaction will need reagents conc. H₂SO₄ and H₂O. The reaction time is 5 minutes at reaction temperature of 20 °C. The yield is about 56%.

Uses of 4H-1-Benzopyran-2-carboxylicacid, 4-oxo-: it can be used to get 4-oxo-4H-chromene-2-carbonyl chloride. This reaction will need reagent PCl₅ and solvent cyclohexane. The reaction time is 45 minutes by heating. The yield is about 89%.

When you are using this chemical, please be cautious about it as the following:
It is irritating to eyes, respiratory system and skin. When you are using it, wear suitable protective clothing, gloves and eye/face protection. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.

You can still convert the following datas into molecular structure:
(1)SMILES: O=C\1c2c(O/C(=C/1)C(=O)O)cccc2
(2)InChI: InChI=1/C10H6O4/c11-7-5-9(10(12)13)14-8-4-2-1-3-6(7)8/h1-5H,(H,12,13)
(3)InChIKey: RVMGXWBCQGAWBR-UHFFFAOYAL

The toxicity data is as follows: