NOVELTY - An enriched desired diastereomeric pair of 3-(6-chloro-5-fluoropyrimidin-4-yl)-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol (IV) is dechlorinated to obtain 2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol (V). The compound (V) is reacted with R-(-)-camphor sulfonic acid to obtain (2R,3S) 2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol camphor sulfonate salt (VI), which is then neutralized with a base to obtain voriconazole (I).    USE - Preparation of voriconazole (claimed).    ADVANTAGE - The method efficiently and economically provides voriconazole with high yield by efficiently recovering raw material by simple process without causing pollution to the environment, without using hazardous lead which causes nervous system problems, headaches, irritability, memory problems and difficulty in sleeping and without chromatographic separation.    DETAILED DESCRIPTION - 4-Chloro-6-ethyl-5-fluoropyrimidine of formula (XI) and 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone of formula (III) are condensed in presence of base (a) and solvent (b) to obtain mixture of desired diastereomeric pair and undesired diastereomeric pair of 3-(6-chloro-5-fluoropyrimidin-4-yl)-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol of formula (IV). The desired diastereomeric pair (IV) is enriched by treating obtained residue with an aromatic solvent (c) and the undesired diastereomeric pair along with unreacted 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone of formula (III) are filtered out. The enriched desired diastereomeric pair (IV) is dechlorinated using catalytic hydrogenation to obtain 2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol of formula (V) (racemic voriconazole). The compound (V) is reacted with R-(-)-camphor sulfonic acid in a solvent (d) to obtain (2R,3S) 2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol camphor sulfonate salt of formula (VI). The obtained salt is neutralized with a base (a') in a solvent (e) to obtain voriconazole of formula (I).    CSA=R-(-)-camphor sulfonic acid.    INDEPENDENT CLAIMS are included for the following:    (1) process of enriching t desired diastereomeric pair of 3-(6-chloro-5- fluoropyrimidin-4-yl)-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol (IV); and    (2) process of recovering unreacted 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone (III), which involves treating mixture of 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone and undesired diastereomeric pair of 3-(6-chloro-5-fluoropyrimidin-4-yl)-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)butan-2-olwith an acid in solvent (x) and obtaining salt of 1-(2,4-difluorophenyl)-2-(1H- 1,2,4-triazol-1-yl)ethanone, and neutralizing the salt using a base (y) to isolate 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone (III).