In many instances the end product of a sequence of biosynthetic reactions inhibits the formation of enzymes responsible for these reactions. Such “negative feedback” effects have been observed in bacteria for amino acids (3-6) and for pyrimidines (7), and the name “enzyme repression” has been coined for them (5). In the case of several amino acids, enzyme repression could be demonstrated by sho...

A facile solid phase synthesis of 2,4,6,7-tetrasubstituted pyrrolo[2,3-d]pyrimidines is described. The synthesis involves a highly efficient five-step route starting from resin-bound dimeric peptoids. To demonstrate the versatility of our method, a representative library of 108 tetrasubstituted pyrrolo[2,3-d]pyrimidines of high quality was synthesized.

The synthesis and characterization of some novel Pyrimidine derivatives have been presented. Acylation of resorcinol followed by nuclear prenylation with isoprene gives Chroman. Chroman on treatment with p-substituted benzaldehydes affords substituted chalcones. Pyrimidines have been prepared from chalcones by condensing with Guanidine hydrochloride in alkali medium. The structure of Pyrimidine...

Recent studies have revealed that various derivatives of 2,4-diaminopyrimidine exhibit profound biochemical reactivity. For example, nearly all 2,4-diaminopyrimidines and their condensed ring systems inhibit the growth of LactobaciZZus casei with folic acid (1). 2,4-Diamino&p-chlorophenoxypyrimidine was found to be a potent antimalarial in that it was active against Plasmodium gallinaceum infec...

Submit Manuscript | http://medcraveonline.com classes of pyrimidines. The pharmaceutical importance of these compounds lies on the fact that they can be effectively used as analgesics, anti-inflammatory, anticonvulsant, insecticidal, herbicidal, antitubercular, anticancer and antidiabetic agents [4-6]. Also, the pyrimidine and aminopyrimidine structures are frequently-occurring motifs in commer...

The study of the action of ferrous bicarbonate plus air on the pyrimidinesl has been continued and the chemical change in the pyrimidine ring examined in more detail. If an aqueous solution of cytosine is treated with the system ferrous sulfate plus sodium bicarbonate plus air, hydrolysis of the amino group occurs with the formation of uracil and the liberation of ammonia. Since uracil is forme...

The preparation of ring-A fused pyrimidines at the steroidal 2,3-position is herein described. The novel steroidal pyrimidines were prepared from the solid phase three-component reaction of 2-hydroxymethylene-3-keto steroids, arylaldehydes and ammonium acetate under microwave irradiation.

The preparation of ring-A fused pyrimidines at the steroidal 2,3-position is herein described. The novel steroidal pyrimidines were prepared from the solid phase three-component reaction of 2hydroxymethylene-3-keto steroids, arylaldehydes and ammonium acetate under microwave irradiation. vailable online 28 March 2009