Abstract
Title compounds bearing substituents on C(2), C(6) and C(8) were prepared from a newly synthesized pyrimidine derivative 11. The new pyrimidine 11 was generated from compound 2 through two different synthetic schemes. In one pathway, compound 2 was nitrosated, reduced and alkylated to produce com pounds 9, 10 and 11 respectively (Scheme). In an alternate route using compound 2 as the starting material, a coupling reaction using the diazonium salt derived from pβmethylaniline afforded the azo derivative 7, which was subsequently alkylated and reductively cleaved to form compounds 8 and 11 respectively (See Scheme). Compound 11 was annulated to the corresponding hypoxanthine derivatives 12β14; compounds 12 and 13 were chlorinated with phosphorus oxychloride, then reacted with amines to yield compound 17 and 20 respectively. Compounds 21, 22 and 23 were obtained by oxidation of the corresponding sulfide as depicted in Scheme. Alkylation of the thiol function of 1 gave a mixture of 3 and 4. Compound 3 was chlo rinated to 5. Nitration of 5 resulted in electrophilic aromatic substitution of the aryl ring and concomitant oxidation of the sulfide to the sulfoxide, producing 6.