The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Synthetic and natural phellandrene.》. Authors are Kondakow, J.; Schindelmeiser, J..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).Quality Control of 5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride. Through the article, more information about this compound (cas:148-51-6) is conveyed.
[Machine Translation of Descriptors]. Carvomenthene, from carvomenthylchloride represented, became after REYCHLER into tertiary carvomenthol and over with 12 mm and 83.5-84.5° boiling. Chloride, D204; 0.932, into tertiary carvomenthene, C10H18, transferred. Boiling point 174-176°; D204; 0.811; nD = 1.45709, molecular refraction 46.23. Dibromide, under strong cooling in petroleum-ether prepared, Kp11; 130-144°. D204; 1.208, optical-inactively, separates no HBr, however alcoholic KOH supplies a hydrocarbon, from the main quantity with 175-180° with boiling D204; 0.825, nD = 1.46693, the smaller part with 180-185°. D204; 0.828, nD = 1.4673; molecular refraction 45.56. Both optical-inactive fractions color intensively raspberry red in a solution of acetic anhydride by H2SO4 and are undoubtedly different from the output hydrocarbon. Under consideration of the formation of the new hydrocarbon from carvomenthol author writes it from SEMMLER, (Ber. German Chem. Society 36. 1779; C. 1903. II. 116) for the phellandrene determined constitution without being able to prove the identity. Phellandrene from phellandrum aquaticum, boiling point 165-168°, D204; 0.844, nD = 1.47575, [α] D20 = 8° 37′. Molecular refraction a mixture of monochloride and dichloride gives 45.28, which probably contains an optical-inactive isomer, with HCl in glacial acetic acid. Monochloride, C10H17Cl, Kp11; 86°, melting point about 110° in the melted out tube, optically dextrorotatory. Dichloride, C10H18Cl2, Kp16; 122.5-125°, D204, 1.006, nD20 = 1.48516.
In addition to the literature in the link below, there is a lot of literature about this compound(5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride)Quality Control of 5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride, illustrating the importance and wide applicability of this compound(148-51-6).
Reference:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia