The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《The heats of hydration and energy contents of cis- and trans-cyclohexane-1,2-dicarboxylic acids, and their primary ions》. Authors are Wassermann, Albert.The article about the compound:cis-Cyclohexane-1,2-dicarboxylic acidcas:610-09-3,SMILESS:O=C([C@H]1[C@@H](C(O)=O)CCCC1)O).Formula: C8H12O4. Through the article, more information about this compound (cas:610-09-3) is conveyed.
The following values were obtained for the cis- and trans-cyclohexane-1,2-dicarboxylic acids and their ions, resp.: heat of combustion, kg.-cal./mole (constant temperature) 931.9, 929.5; heat of solution + first heat of ionization, -7.49, -6.48; energy content of primary anion in dilute solution, kg.-cal./mole 939.4, 936.0; mol. volume at 0° 126.5, 120.4; second heat of ionization +0.30, +0.24. The first ionization constant of the cis acid increases with rise in temperature, while that of the trans decreases. This leads to the conclusion that the trans ion is more hydrated than the cis ion, although the heat of hydration of the undissociated cis is not measurably greater than that of the trans acid.
In addition to the literature in the link below, there is a lot of literature about this compound(cis-Cyclohexane-1,2-dicarboxylic acid)Formula: C8H12O4, illustrating the importance and wide applicability of this compound(610-09-3).
Reference:
Benzisoxazole – Wikipedia,
Benzisoxazole – an overview | ScienceDirect Topics