The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Vitamin B6. II. Reactions and derivatives》. Authors are Harris, Stanton A..The article about the compound:5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloridecas:148-51-6,SMILESS:OC1=C(C)C(CO)=CN=C1C.[H]Cl).Electric Literature of C8H12ClNO2. Through the article, more information about this compound (cas:148-51-6) is conveyed.
Vitamin B6-HCl (I) in an equal mixture of C5H5N and Ac2O, allowed to stand overnight and then heated on a steam bath for 20 min., gives vitamin B6 triacetate-HCl [2-methyl-3-acetoxy-4,5-bis(acetoxymethyl)-pyridine-HCl], m. 157°; it is stable in 0.01 N HCl but is slowly hydrolyzed in 0.01 N alkali at 37°. Vitamin B6 dibromide-HBr (II) and 3 equivalents AcOAg in a 22% solution of AcOK in AcOH, heated on the steam bath for 0.5 hrs., give 25% of vitamin B6 diacetate-HCl [2-methyl-3-hydroxy-4,5-bis(acetoxymethyl) pyridine-HCl], m. 160-1°; the aqueous solution gives a good FeCl3 test; it has the same relative stability as the tri-Ac derivative Reduction of II with a PdBaSO4 catalyst in EtOH gives 40% of 2,4,5-trimethyl-3-hydroxypyridine, m. 178°; HCl salt, m. 216°. Catalytic reduction of I with the Adams catalyst gives 2,4-dimethyl-3-hydroxy-5-hydroxymethylpyridine-HCl, m. 267-8°; this is weakly active for the growth and promotion of acid formation by Streptobacterium plantarum, whereas III is inactive. I, exactly neutralized with 1 equivalent of MeONa in MeOH and heated at 125° for 4 hrs., gives a small yield of 2-methyl-3-hydroxy-4-methoxymethyl-5-hydroxymethylpyridine-HCl (III), m. 181°.
Compounds in my other articles are similar to this one(5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride)Electric Literature of C8H12ClNO2, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.
Reference:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia