Im. El-deen et Hk. Ibrahim, Synthesis and some reactions of 2-mercapto-4-hydroxypyrimidine [3,4-(b)under-bar]coumarin, PHOSPHOR SU, 160, 2000, pp. 241-250
Citations number
7
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
2-Mercapto-4-hydroxypyrimidine[3,4-b]coumarin (3) was prepared by the conde
nsation of 3-ethoxycarbonylcoumarin (1) with thiourea. Alkylation of 3 with
alkyl halides (namely, methyl iodide, ethyl iodide, benzyl chloride and et
hyl chloroacetate) yielded the corresponding 2-alkylthio-4-hydroxypyrimidin
e[3,4-b]coumarin 4a-d. Hydrolysis of 4d with 2 N NaOH gave acid derivative
6, and condensation of 4d with hydrazine hydrate gave hydrazone 7. 1,3,4-Ox
adiazol derivatives 9 and 11 were obtained by the reaction of 7 with aromat
ic aldehydes to give aryldene derivatives 8a,b. Cyclization of 8 followed w
ith bromine in acetic acid and treatment of 7 with ethyl chloroformate in p
yridine and sodium acetate led to 11.