Ortho Phenylinediamine Boiling Point: 252 A C

O-phenylenediamine is used to prepare tiabendazole, pyrazinamide, morinamide, clemizole and chlormidazole. It is involved in the synthesis of benzimidazole by reacting with carboxylic acids and their derivatives. It is also used to prepare quinoxalinedione and mercaptoimidazoles by condensation with dimethyl oxalate and xanthate esters respectively.
Chemical formula : C6H8N2
Molar mass : 108.144 gA.mol-1
Density : 1.031 g/cm3
Melting point : 102 to 104 A C (216 to 219 A F; 375 to 377 K)
Boiling point : 252 A C (486 A F; 525 K) Other sources: 256 to 258 A C (493 to 496 A F; 529 to 531 K)
Solubility in water : soluble in hot water
Acidity (pKa) : 0.80 (doubly protonated form; 20 A C, H2O)
4.57 (conjugate acid; 20 A C, H2O)[2]