2-Mercapto-4-methylpyrimidine

The reaction is carried out in both acidic and basic media. Thus, for example, the interaction of 4-diethylaminobut-3-en-2-one with thiocarbamide is performed at 75°C for 30 h (EtOK, EtOH) to result in 54% yield of the major product. The existence of two tautomers 274 and 275 was proved for 2-mercapto-4-methylpyrimidine (Y = S) by IR and H NMR spectroscopy (76ZOR2063). 

The synthesis of 2-substituted pyrimidines from 1,3-dicarbonyl compounds and urea derivatives was first described by Evans2 and was later improved by Hunt, McOmie, and Sayer3 for the preparation of 2-mercapto-4,6-dimethylpyrimidine. Burness4 employed 3-ketobutyraldehyde acetal in this procedure to give 2-mercapto-4-methylpyrimidine. 2-Mercaptopyrimidine has been prepared from 1,1,3,3-tetraethoxypropane and thiourea by variations of this basic method 3 6 6 as well as by the reaction of 2-chloropyrimidine with thiourea 1 or sodium hydrosulfide.8... 

An example of application of this reaction employing NH OAc as a source of ammonia is depicted in Scheme 12.3. It is a key step in the preparation of a pyrimidine-imidazole-based library, where their biological activities were under study [7-9]. Thus, using glyoxal dimethyl acetal 11, ammonium acetate, and the required asymmetrical 1,2-diketone 10, prepared from 4-fluorobenzoate 9 and 2-mercapto-4-methylpyrimidine 8, the key intermediate 12 was obtained in good yield (86%). 

Substituted-4-hydroxy-6-methylpyrimidines are formylated in the 5-position when the 2-substituent (e.g. NH2, OH) is sufficiently electron releasing. The related 4-mercapto compounds gave only the ortho-thio-esters. ... 

Heating 5-hydroxy-3-mercapto-7-phenyl-1,2,4-triazolo[4,3-a]pyrimidine (145) with aniline gave the 2-anilino-4-hydroxy-6-methylpyrimidine (144)... 

Lactonization of ta-hydroxy esters to macrolides. Gerlach and co-workers have reported that silver salts can catalyze the cyclization of v-hydroxy-2-pyridinethiol esters to macrolides (6, 246 7, 142). Nimitz and Wollenberg have found that silver perchlorate has an even more pronounced and consistent effect on the cyclization of (u-hydroxy thiolesters of 2-amino-4-mercapto-6-methylpyrimidine, Optimal yields are obtained with use of 1.1 equiv. of the silver salt. In addition, high dilution is not necessary. In the example cited, the yield of the lactone in the absence of the catalyst is 41%. 

Thymine. S-Methyt-2,4(IHt3H)-pyritnidinedione 5 -metbyluracil 2,4 -dihydroxy - 5 -methylpyrimidine. C,H4 -N202 mol wt 126.11. C 47.62%, H 4.80%, N 22.22%, O 25.37%. A pyrimidine derivative constituent of nucleic acids. Originally isolated from thymus nucleic acid Levene, Z. Physiol Chem. 39, 4 (1903). Prepn by heating 2-ethyl-mercapto-4-hydroxy-5-methyl pyrimidine Wheeler, Mer-... 

Preparative Methods readily prepared from commercially available 2-amino-4-chloro-6-methylpyrimidine, which is treated with NaS-HaO (5 equiv) in degassed propylene glycol at 140 °C for 3 h. The solution is diluted with H2O and neutralized with acetic acid. The collected precipitate is recrystaUized from ethanol, giving pure 2-arnino-4-mercapto-6-rnethylpyriniidine, which is dimerized with iodine in boiling methanol containing potassium carbonate. 

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