| Title:  5,6-Dimethylbenzimidazole CAS Registry Number:  582-60-5 Molecular Formula:  C9H10N2 Molecular Weight:  146.19 Percent Composition:  C 73.94%, H 6.89%, N 19.16% Literature References:  Obtained by acid hydrolysis of vitamin B12:  Brink, Folkers, J. Am. Chem. Soc. 71, 2951 (1949); 72, 4442 (1950).  Synthesis by refluxing 4,5-diamino-1,2-dimethylbenzene and formic acid in 4N HCl:  Hobrecker, Ber. 5, 921 (1872); Phillips, J. Chem. Soc. 1928, 2393. Properties:  Crystals from ether, mp 205-206°.  Sublimes at 140° and 3 mm.  uv max (95% ethanol acidified with HCl to be 0.01N):  274.5, 284 nm.  Alkaline to litmus.  Soluble in water, chloroform, ether; freely sol in dil acids. Melting point:  mp 205-206° Absorption maximum:  uv max (95% ethanol acidified with HCl to be 0.01N):  274.5, 284 nm  |