Synthesis and antibacterial activity of pyrimidinylureidopenicillins.

The 6R-[(R)-2-[3-[5-pyrimidinyl]ureido]-2-(4-hydroxyphenyl) acetamido]-penicillanic acids (10), prepared by two synthetic routes, exhibit broad antimicrobial activity against Gram-positive and Gram-negative bacteria. Their structure activity relationships are discussed. 6R-[(R)-2-[3-[2-(p-Aminosulfonyl)anilino-4-hydroxy-5-pyrimidinyl] ureido]-2-(4-hydroxyphenyl)acetamido]-penicillanic acid, sodium salt (VX-VC 43, 10m), the most active compound, shows very low MIC (minimal inhibitory concentration) values against clinically important Gram-negative bacteria, primarily Pseudomonas aeruginosa.