Molecular Formula: C₇H₉BO₃
Molar mass: 151.9556 g/mol
Density: 1.17 g/cm³
Flash Point: 146.9 °C
Index of Refraction: 1.524
Melting point: 105-110 °C(lit.)
Boiling Point: 319.3 °C at 760 mmHg
Vapour Pressure: 0.000142 mmHg at 25°C
Appearance: white to light yellow crystal powder
Structure of 2-Methoxyphenylboronic acid(5720-06-9) :
                
Synonyms: boronic acid, B-(2-methoxyphenyl)- ; (2-Methoxyphenyl)boronic acid ; o-Methoxyphenylboronic acid ; Phenylboronic Acid,17
Product Categories: Heterocyclic Compounds;Boronic Acids;Substituted Boronic Acids;Boronic Acid series;Boron, Nitrile, Thio,& TM-Cpds;Alkoxy;Aryl;Organoborons

Carcinogenicity of 2-Methoxyphenylboronic acid(5720-06-9) hasn't been listed as a carcinogen by  NTP, IARC,ACGIH, or CA Prop 65 .And its toxicological properties have not been fully investigated.

Hazard Note: Irritant
Hazard Codes: Xi
Risk Statements:
36:  Irritating to the eyes
37:  Irritating to the respiratory system
38:  Irritating to the skin
Safety Statements:
26:  In case of contact with eyes, rinse immediately with plenty of water and seek medical advice
36:  Wear suitable protective clothing 
37:  Wear suitable gloves
39:  Wear eye/face protection

 2-Methoxyphenylboronic acid(5720-06-9) is hazardous,so the first aid measures and others should be known .Such as:
Skin: Get medical aid. Should flush skin with plenty of water immediatelyfor at least 15 minutes while removing contaminated clothing and shoes.
Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids.Then get medical aid soon. 
Inhalation: Remove from exposure and move to fresh air immediately.And as soon as to get medical aid.
Ingestion: Wash mouth out with water,and get medical aid immediately.
The 2-Methoxyphenylboronic acid(5720-06-9) can be stable under normal temperature and pressure conditions.It is not compatible with strong oxidizing agents and you must not take it with incompatible materials .And also prevent it to broken down into hazardous decomposition products: Carbon dioxide,carbon monoxide.