Synthesis of novel impurities in 2-(2-(4-fluorophenyl)-2-oxo-1-phenylethyl)-4-methyl-3-oxo-N-phenylpentanamide; an atorvastatin intermediate

(3R,5R)-7-(3-(phenylcarbamoyl)-5-(4-fluorophenyl)-2-isopropyl-4-phenyl-1H-pyrrol-1-yl)-3,5-dihydroxy-heptanoic acid, calcium salt (2:1)trihydrate (1), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, was demonstrated to be effective in reducing both triglyceride and cholesterol. In present communication, two novel impurities i.e.,2-acetyl-4-(4-fluorophenyl)-4-oxo-N,3-diphenylbutanamide (18) and 2-(2-(3-fluoro phenyl)-2-oxo-1-phenylethyl)-4-methyl-3-oxo-N-phenylpentanamide (19)of 2-(2-(4-fluorophenyl)-2-oxo-1-phenylethyl)-4-methyl-3-oxo-N-phenylpentanamide (2),were reported along with their identification and isolation. The compounds were characterized by spectral techniques such as IR, 1HNMR, 13C NMR and mass.