Synthesis and Biological Activities of some Pyrimidine derivatives: (A-Review)

Nitrogen containing synthetically and biologically important heterocyclic ring system namely pyrimidine possess both biological and pharmacological activities and defend as aromatic six heterocyclic with 1 and 3 nitrogen atom in ring. Preparation of pyrimidine via different methods offer its importance in fields of medicinal chemistry and Chemistry. Pyrimidines and their derivatives act as anti-inflammatory, anti-malaria, anti-tumor, cardiovascular agents, anti-neoplastic, anti-tubercular, anti-HIV, diuretic, anti-viral, anti-microbial, analgesic. This review give light up on biological and pharmacological activities of pyrimidine nucleus.


INTROdUCTION
B e c a u s e o f i t s d i f fe r e n t i n t r i n s i c biological proper ties Pyrimidine it become attractive for researcher in medicinal chemistry field 1 , pyrimidines are used as Mycobacterium tuberculosis 2 , antioxidants 3 , antidiabetics 4 . Heterocycles which contain pyrimidopyrimidine have therapeutic proper ties ant allergic 5 , a n t i ox i d a n t 6,7 , a n t i v i ra l 8 , a n t i h i s t a m i n i c 9 , cytostatic, immunomodulating 10-12 herbicidal 13 , anticonvulsant 14 activities. pyrimidines exhibit antimicrobial activities such as fungicidal 15 , antitoxoplasma 16 , antimalarial 17,18 , antibacterial 19,20 , antifilerial 21  Pyrimidine nucleus act as antimicrobial agent 25 so they are important chemicals in agricultural and drugs.
Pyrimidines comprise important interesting group of antibacterial drugs, which have made a major impact on the field of antibacterial chemotherapy particularly in the past few years. Pyrimidine nucleus act as chemotherapeutic agents and exhibit anticancer activities 26 .

Synthesis and biological activities of pyrimidine derivatives
Reaction of diazonium salt (1) and (2) in solution of NaOH yield the corresponding (3) which react with sulphonamide derivatives diazonium salt give compound (4 a-c) (Scheme 1) 27 , compounds (4b) and (4c) exhibit good results against anticancer and antifungal efficacies, Gram-negative and gram positive respectively also both pyrimidine derivatives azo dyes and thiazolyl azo dyes derivatives displayed good properties on polyester fabrics, but thiazolyl azo dyes derivatives exhibit good properties than pyrimidine derivatives azo dyes 27 . sulphonamidediazobenzene derivatives exhibit pharmacological activities so it used as nontextile 27 .  (6) in solution of kOH at 298k afford chalcones (7). Reaction of chalcones (7) with urea and potassium hydroxide in methyl alcohol yield the corresponding(8) Also treatment of chalcone (7) with Thiourea and kOH in methyl alcohol give compound(9), treatment of chalcone (7) and hydrazine monohydrate in AcOH provide the corresponding(10), the product recrystallized with ethanol 28 .
Reaction of triazole (11) with (12 a) by using different solvent such as methanol/HCl, ethanol, acetic acid, there is no reaction but the reaction of mixture in DMF using reflux and heat in presence of potassium carbonate anhydrous provide triazolo pyrimidine(15a) or (18a).
The synthesized compounds exhibit antifungal, antioxidant and antibacterial effect 33   Pyr imidine (58) wa s p r e p a r e d by treatment of methylthiopyrimidinone (55) with bromomethylacetylene (56) in k 2 CO 3 /DMF at room temperature (Scheme 16) 34 .

Treatment of pyrimidine (57) and (59a)
in the absence of catalyst lead to there is no formation of product formed after 3 h the reaction give maximum of the yield when use CuI/Mg-Al-lDH catalyst [28, this method was easy, clean reaction, short reaction time and high yield 34 .

CONCLUSION
The current study gives a portrayal of the biological and natural significance of heterocyclic related pyrimidine nucleus, these pyrimidine unit exhibited significant and assorted organic properties, the examined pyrimidine derivatives prepared by cyclocondensation reaction, also through reaction of chalcone with different 1, 3-dinucleophiles. Pyrimidine derivatives that have biological activities.

ACkNOwLEdgMENT
The author grateful to Jouf University, Saudi Arabia and Aswan University, Aswan, Egypt is gratefully acknowledged. A. R. J. Chin. Chem. Soc., 2001,