Synthesis of new pyrimidine and pyrido[2,3-D]pyrimidine derivatives with evaluation of antitumor activity

The carbothioamide derivatives of 6-aminopyrimidine-2,4-[1H,3H]dione [2a-c] were prepared by the reaction of different isothiocyanates with 6-aminopyrimidine-2,4-[1H,3H]-dione [1]. Also, azo derivatives of pyrimidine-2,4-diont [3a-d] were obtained, while the Mannich bases [4a,b] were produced by the reaction of compound 1 with formalin and p-aminobenzene sulfonamide derivatives [sulfa drugs]. Pyrimido[4,5-d]pyrimidine sulfonamide [5] was prepared by the reaction of compound 1 with excess of formalin solution and sulfadiazine. Furthermore, compound 1 was condensed with some aromatic aldehydes to give the Schiff's bases [6a-d] which on treating compounds [6b,d] with chloroacetylchloride gave compounds [7a,b].The pyrido[2,3-d]pyrimidine derivatives [8a-c, 9a-c, 10a-d] and [11a-c] were also synthesized. The antitumor activity of some of the synthesized compounds was evaluated

Pyrazole-4-carboxaldehyde from chromone-3-carboxaldehyde

It has been perviously reported that the action of hydrazine hydrate on chromones affordes the respective disubstituted pyrazoles [1]. Szabo et al.[2] reported in 1979 that hydrazine hydrate attacks 3-phenylchromone [isoflavone] at C-2 to give 3-[Q-hydroxyphenyl]- 4-phenylpyrazole. Also, the cyclization of acetophenone semicarbazone to 3-phenyl-pyrazole-4-carboxaldehyde was reported by Kira et al. [3]