Isomeric iso‐butoxy phenylboronic acids (ortho‐, meta‐, para‐) were synthesized and their properties such as pKa and thermal stability have been compared. Molecular and crystal structure of the para isomer was determined by single crystal XRD method. DSC and TGA measurements of all the isomers have been carried out to study their dehydration as well as thermal stability. The results show that the position of the substituent in phenylboronic acids influences their acidity as well as possible formation of the corresponding boroxines.