Raltegravir Diketo Ethoxy Impurity synthesis

Yield:1193687-88-5 25 mg

Reaction Conditions:

with triethylamine in chloroform at 0 - 20; for 2.5 h;

Steps:

Synthesis of ethyl-(2-(4-(4-fluorobenzylcarbamoyl)-1,6-dihydro-5-hydroxy-1-methyl-6-oxopyrimidin-2-yl)propan-2-ylcarbamoyl)formate (4)

In a clean and dry 3000 mL round bottom flask, it was taken 400 mL of chloroform, 40 g of compound 8 and 38 g of triethylamine at room temperature under gentle stirring, then added 32 g of ethyl oxalyl chloride dropwise over a period of 0.5 h at 0-5 C. The reaction mass was maintained for 1 h at 0-5 C and another 1 h at room temperature until the reaction get complies in TLC. After completion of the reaction added 1N HCl (200 mL) to the wine red colour reaction mass to remove excess of triethylamine, the obtained organic residue after distillation under reduced pressure was isolated in isopropyl ether (IPE) and got 25 g pure material. 1H NMR (DMSO-d6): δ 12.21 (s, 1H),9.48 (s, 1H), 9.06 (t, 1H), 7.38 (t, 2H), 7.16 (t, 2H), 4.51 (d, 2H),3.36 (s, 3H), 1.64 (s, 6H); 13C NMR (DMSO-d6): δ 168.45, 162.53, 160.52, 160.12, 158.59, 156.92, 151.74, 145.72, 134.90,134.88, 129.47, 124.40, 115.25, 115.04, 62.19, 57.16, 41.65,32.96, 26.90, 13.78. Mass: M+: 434.42, M-H: 433.3 (-ve scan).

References:

Rao, S. Venkat;Potluri, Vamsi Krishna;Potluri, Ramesh Babu [Asian Journal of Chemistry,2019,vol. 31,# 11,p. 2618 - 2622]