Medicinal interest pyrimidine derivatives

Irreversible lactim-lactam tautomerization was recognized a long time ago and is generally achieved by either heat or catalysts. One of the synthetic applications was reported by Knorr as early as 1897. Later, this reaction was first applied to the synthesis of pyrimidine nucleoside by Johnson and Hilbert, thus being called the Hilbert-Johnson reaction (HJR). The reaction has been employed as one of protocols for the preparation of pyrimidine nucleosides. The biological and medicinal interest in pyrimidine affords further impetus to prepare new types of derivatives. Because of the synthetic utility of the HJR for synthesis of pyrimidine nucleosides, a more sophisticated version of the HJR has been developed by Vorbriiggen (the silyl HJR VHJR) employ-... 

SOME PYRIMIDINES OF BIOLOGICAL AND MEDICINAL INTEREST—PART III midine-5-(a-haloacylamides) were reported to inhibit the multiplication of vaccinia virus in chick embryonic tissue. The isocytosine derivative (LX), as well as the corresponding uracil and 2-amino, 6-dimethyl analogues, were the most active of the compounds tested (m.i.c., 10 mg/1) [365]. 

SOME PYRIMIDINES OF BIOLOGICAL AND MEDICINAL INTEREST—PART III A number of 4,6-disubstituted 5-nitropyrimidines have been claimed to be useful as fungicides [471]. A 100 per cent control of typical fungi was attained with a 0-1 per cent concentration of 5-nitropyrimidines having the following substituents 4,6-dichloro-, 4-chloro-6-amino-, 4,6-diamino, and 4,6-di-hydroxy-. The 4,6-dichloro derivative (XCII) is the best. All compounds maintained some activity at 0-001 per cent concentrations. 

Imines 848 are promising reagents for the synthesis of fluoroalkyl-substituted pyrimidinines and their fused analogues since they lead to functionalized low-molecular-weight compounds which are of special interest for medicinal chemistry. Many CCN binucleophiles discussed in this section were also introduced into reaction with 848. In particular, formation of pyrimidine derivatives 911 in reaction of 848 and enamines 909 (including compounds 859 discussed above) was described recently. The most likely initial step is the imidoylation of the nucleophilic carbon... 

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