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Chapter 1
Synthesis of functionalized pyrimidines
1.1 Introduction
The pyrimidine fragment is present in the molecules of a series of biologically
active compounds, many of which have found use in medical practice (soporific, antiinflammatory,
antitumor, and other products). 1,2 In this connection, great attention has
recently been paid to the derivatives of pyrimidine, including their hydrogenation
products. The first investigation into the synthesis of pyrimidine nucleus appeared
more than a hundred years ago and subsequently several methods for the synthesis of
dihydropyrimidine were reported and their physicochemical properties has been
studied (e.g., the Biginelli reaction). 3 Further, the high reactivity and wide range of
biological activity associated with these scaffolds have been demonstrated in the
literature. For example, 2-substituted 5-alkoxycarbonyl-4-aryl-l,4-dihydropyrimidines
(structural analogs of Hantzsch esters) are modulators of the transport of calcium
through membranes. 4-7 Many hydrogenated pyrimidines exhibit antimicrobial, 8
hypoglemic, 9 herbicidal, 10 and pesticidal 11 activity. Publications devoted to these
problems have been summarized in a number of reviews. 9-14
Pyrimidines have a long and distinguished history extending from the days of
their discovery as important constituents of several biological molecules such as
nucleic acids, cofactors, various toxins, to their current use in the chemotherapy of
AIDS. All these compounds yield great promise for the treatment of retro virus
infections in humans.
Alloxan (1) is known for its diabetogenic action in a number of animals. 15
Uracil (2), thymine (3) and cytosine (4) are the three important constituents of nucleic
acids (Figure-1).
Figure-1
The pyrimidine ring is also found in vitamins such as thiamine (5), riboflavin
(6) (Figure-2) and folic acid (7). 16 Barbitone (8) is the first barbiturate hypnotic,
sedative and anticonvulsant are pyrimidine derivatives (Figure-3).
Department of Chemistry, Saurashtra University, Rajkot-360005 1