To improve the quality control upon substance and product of dolutegravir, three chiral impurities should be obtained.Starting with 1-(2, 2-dimethoxyethyl)-5-methoxy-6-(methoxycarbonyl)-4-oxo-1, 4-dihydropyridine-3-carboxylic acid, the enantiomer impurity A was obtained after hydrolysis, cyclization, condensation and Me removal reactions.Key intermediate 9 could be prepared by condensation and hydrolysis, then cyclizaiton, hydrolysis, condensation and Me removal reactions to give two diastereoisomer impurities B and C with different amino butanol reagents.Three impurities were all confirmed with MS and NMR.The purities were all above 98%, and the values of ee were in the range of 96%-99%.Those impurities met the requirement of anal. method development, and provided scientific support for impurity study and control strategy of dolutegravir.♂