The 4-Methoxyphthalic acid, with CAS registry number 1885-13-8, has the systematic name of 4-methoxybenzene-1,2-dicarboxylic acid. And its IUPAC name is 4-methoxyphthalic acid. And the chemical formula of this chemical is C₉H₈O₅. What's more, its EINECS is 217-546-2. 

Physical properties of 4-Methoxyphthalic acid: (1)ACD/LogP: 1.09; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -1.62; (4)ACD/LogD (pH 7.4): -3.01; (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: 5; (10)#H bond donors: 2; (11)#Freely Rotating Bonds: 3; (12)Polar Surface Area: 61.83 Å²; (13)Index of Refraction: 1.59; (14)Molar Refractivity: 46.79 cm³; (15)Molar Volume: 138.4 cm³; (16)Polarizability: 18.54×10^-24cm³; (17)Surface Tension: 61.7 dyne/cm; (18)Enthalpy of Vaporization: 67.92 kJ/mol; (19)Vapour Pressure: 6.46E-07 mmHg at 25°C.

When you are using this chemical, please be cautious about it as the following:
The 4-Methoxyphthalic acid irritates to eyes, respiratory system and skin. When use it, wear suitable protective clothing, gloves and eye/face protection. If 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(O)c1cc(OC)ccc1C(=O)O
(2)InChI: InChI=1/C9H8O5/c1-14-5-2-3-6(8(10)11)7(4-5)9(12)13/h2-4H,1H3,(H,10,11)(H,12,13)
(3)InChIKey: JKZSIEDAEHZAHQ-UHFFFAOYAT
(4)Std. InChI: InChI=1S/C9H8O5/c1-14-5-2-3-6(8(10)11)7(4-5)9(12)13/h2-4H,1H3,(H,10,11)(H,12,13)
(5)Std. InChIKey: JKZSIEDAEHZAHQ-UHFFFAOYSA-N