This chemical is called 4-Chlorophthalic acid, and its systematic name is 4-chlorobenzene-1,2-dicarboxylic acid. With the molecular formula of C₈H₅ClO₄, its molecular weight is 200.58. The CAS registry number of this chemical is 89-20-3, and its product category is Pharmacetical.

Other characteristics of the 4-Chlorophthalic acid can be summarised as followings: (1)ACD/LogP: 1.98; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -1.2; (4)ACD/LogD (pH 7.4): -2.15; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 4; (10)#H bond donors: 2; (11)#Freely Rotating Bonds: 2; (12)Polar Surface Area: 52.6 Å²; (13)Index of Refraction: 1.63; (14)Molar Refractivity: 45 cm3; (15)Molar Volume: 126.4 cm³; (16)Polarizability: 17.84×10^-24cm³; (17)Surface Tension: 71.2 dyne/cm; (18)Density: 1.586 g/cm³; (19)Flash Point: 195.4 °C; (20)Enthalpy of Vaporization: 68.58 kJ/mol; (21)Boiling Point: 399.5 °C at 760 mmHg; (22)Vapour Pressure: 4.22E-07 mmHg at 25°C.

Uses of this chemical: The 5-chloro-isoindole-1,3-dione could be obtained by the reactant of 4-Chlorophthalic acid. This reaction needs the reagent of ammonium carbonate. The yield is 91 %. This reaction should be taken for 2 hours at the temperature of 300 °C.

You can still convert the following datas into molecular structure: 
1.SMILES: O=C(O)c1c(cc(Cl)cc1)C(=O)O
2.InChI: InChI=1/C8H5ClO4/c9-4-1-2-5(7(10)11)6(3-4)8(12)13/h1-3H,(H,10,11)(H,12,13)
3.InChIKey: DVIPPHSQIBKWSA-UHFFFAOYAB