6-Amino-2,4-dimethyl pyrimidine

Finally, Katritzky et al.sii have measured first-order rate coefficients for deuteration of pyrimidines by deuterated sulphuric acid (Table 152), and all pD and —D0 values given in the Table refer, as in the earlier work, to a temperature of 20 °C. For 2-aminopyrimidine, reaction clearly occurs on the free base and comparison of the data with the earlier work on anilines and by making a number of assumptions, conjugate acid at higher acidities is apparent and this follows the previously established pattern. This work yielded a value of 0.55 for [Pg.236]

In addition to amino-methylamine exchanges, amino-benzylamine exchanges were found. When iv-benzyl salts of pyrimidine, 4,6-dimethyl-pyrimidine, and 4-t-butylpyrimidine react with liquid ammonia, the respective debenzylated compounds were isolated (Scheme III.9) (82JHC3739). 

The dinuclear compound 16 was prepared from LnCp3 and 2-amino-4,6-dimethyl-pyrimidine. 

Am no-1,L-d i methyI benzene, AN78 1-Am i no-3, -d i methy 1 -5 -b romo-thiazoifum iodide, AE42 U-Amino-2,6-dimethyl pyrimidine, AH60... 

The API sulfamerazine undergoes hydrolysis on the sulfonamide group to form the products shown in Figure 63 (104). The API sulfamethazine degrades under acidic conditions to produce sulfanilic acid and 2-amino-4,6-dimethyl-pyrimidine (105). Additionally, aryl hydrolysis also occurs to yield the 2-hydroxy-4-methylpyrimidine and sulphanilamide. 

Scheme 13. Interpretation of the electrochemical and chemical behaviour observed for 4-amino-2,6-dimethyl pyrimidine (Ref.li))...

These two herbicides have been prepared177 by condensation of 14C-labelled heterocycles 179 and 180 with methyl 2-(sulphonylisocyanate)benzoate 178 (equations 65 and 66). [2-14C] 2-Amino-4,6-dimethyl pyrimidine 179 has been obtained from [14C]guani-... 

The addition of chlorothioformyl chloride to a-amino-N-heterocycles can clearly take place in the opposite sense, the sulfur atom appearing adjacent to the exocyclic nitrogen of the starting material. This occurs when 2-aminothiazole or 2-amino-A2-thiazoline react in ethanol-free chloroform, resulting in thiazolo[2,3-c]-l,2,4-thiadiazol-3-one (186) or its 5,6-dihydro analog. The structure of the latter has been confirmed by X-ray analysis. 2-Amino- (and 4-amino-2,6-dimethyl)pyrimidine similarly afford 1,2,4-thiadiazolo[4,3-a]pyrimidin-3-one (187, R = H, 34%) and 5,7-dimethyl-l,2,4-thiadiazolo[4,3-c]pyrimidin-3-one (39%), respectively. Possible mechanisms of the reactions have been discussed.164... 

Aromatische und aliphatische Nitrile trimerisieren sich unter Druck zu sym.-Triazinen oder zu Pyrimidinen. Bei niederen Drucken von ca. 7000 atm und einer Temperatur von ca. SO C ist die Anwesenheit von basischen Katalysatoren erforderlich. So erhalt man z. B. aus Acetonitril neben dem sym.-Trimethyltriazin auch etwas 4-Amino-2,6-dimethyl-pyrimidin (2 i). Bei hoheren Drucken wie 50000 atm und hoheren Tem-peraturen wie 400° C erhalt man in kurzer Zeit eine fast 100%ige Aus-beute der sym.-Triazine 244). 

Pyrazolopyrimidines, amino-acidity, 5, 309 alkylation, 5, 310 N-oxide synthesis, 5, 324 synthesis, 4, 525 5, 328 Pyrazolopyrimidines, dimethyl-synthesis, 5, 316 Pyrazolo[ 1,5-a]pyrimidines electrophilic attack, 5,311 synthesis, 5, 271, 320, 331 Pyrazolo[ 1,5-c]pyrimidines electrophilic attack, 5, 312 Pyrazolo[3,4- d]pyrimidines nucleophilic attack, 5, 313 synthesis, 5, 161, 272, 323, 334 tautomerism, 5, 309 Pyrazolo[4,3-d]pyrimidines alkylation, 5, 310 synthesis, 5, 272... 

Pyrimidine-2,4(IH,3f/)-dione, 6-amino-5-benzyliminomethyl-1,3-dimethyl-synthesis, 3, 122... 

Pyrimido[4,5-d]pyrimidine-2,4( 1 H,3H)-dione, 5-amino-1,3-dimethyl-synthesis, 3, 350... 

---