Further studies and synthesis of new pyrido[2,3-d]-pyrimidines, thiazolopyridopyrimidines: the reaction of 6-aminothiouracil with cyclic alpha, beta-unsaturated ketones

ABSTRACT

6-aminothiouracil [1] reacts in boiling dimethylformamide with cyclic alpha, beta -unsaturated ketones [2] yielding the 7-aryl-thioxo 5, 6, 7, 10, 11, 12-hexahydro, 7-aryl-10-thioxo-5, 6, 10, 11-tetrahydro -9H-benzo [h] pyrimido [4, 5-b]quinolin-8-one systems[4, 5] and 5-aryl-2-thioxo-1, 2, 3, 5, 6, 7, 8, 9, 10, 11-decahydro-, 5-aryl-2-thioxo-1, 2, 3, 6, 7-, 8, 9, 10-octahydrocyclohepta [5, 6] pyride [2, 3-d] pyrimidin-4-one[8, 9], respectively. The latter pyridopyrimidines reacted with chloroacetic acid in presence of an aidehyde to furnish a 10- arylidene -7- aryl- 5, 6- dihydro-11- thia-8a, 12, 13- triazabenzo- [a] cyclopenta [i] anthracene- 8, 9- dione or 2 -arylidene -5- aryl- 7, 8, 9, 10- tetrahydro -6H-1-thia-3a, 11, 12-triaza-cyclohepta [b] cyclopenta [g] naphthalene -3, 4-dione [10, 11]. The reaction with halo-derivatives such as methyliodide, 3-chloro-2.4 pentanedione furnished the alkylated pyrimidines 12, 14, 16, 17, 19, 20. The latter products reacted with hydrazine hydrate to give the hydrazine derivatives 21. The cyclization of 12, 14 to 13, 15 using acetic anhydride/pyridine have been reported