Process for preparing voriconazole by using new intermediates
Provided is a process for preparing Voriconazole represented by Chemical Formula 1. More particularly, the process for preparing Voriconazole of Chemical Formula 1 includes: carrying out the Reformatsky-type coupling reaction between a ketone derivative of Chemical Formula 4 and a pyrimidine derivative of Chemical Formula 5 to obtain a compound of Chemical Formula 3; reacting the substituents halo and oxysulfonyl with a hydrogen donor to obtain racemic Voriconazole of Chemical Formula 2; and carrying out optical isolation of the racemic Voriconazole by adding an adequate optically active acid thereto to obtain Voriconazole having high optical purity with high cost-efficiency and high yield.
1. A process for preparing Voriconazole of the following Chemical Formula 1, comprising the steps of:
1) carrying out the Reformatsky-type coupling reaction between a compound of the following Chemical Formula 4 and a compound of the following Chemical Formula 5 to obtain a compound of the following Chemical Formula 3;
2) removing the substituents X 1 , X 2 and OSO 2 R from the compound of Chemical Formula 3 to obtain racemic Voriconazole of the following Chemical Formula 2, with the proviso that X 1 and X 2 are not removed when they both represent H; and
3) separating the isomers of the compound of Chemical Formula 2 with an optically active acid:
wherein X 1 and X 2 independently represent H or halo; and
R is C 1 -C 4 alkyl or substituted or non-substituted phenyl, wherein the substituted phenyl may be substituted with at least one substituent selected from the group consisting of C 1 -C 4 alkyl, alkoxy, halo, nitro and oxo.
2. The process according to claim 1 , wherein the Reformatsky-type coupling reaction in step 1) is carried out at a temperature ranging from −15° C. to 0° C.
3. The process according to claim 1 , wherein step 2) is carried out by using Pd/C, Raney nickel or zinc as a catalyst.
4. The process according to claim 3 , wherein Pd/C is used in an amount of 2-30 wt % based on the amount of the compound of Chemical Formula 3.
5. The process according to claim 1 , wherein step 2) is carried out by using hydrogen or ammonium formate as a hydrogen donor.
6. The process according to claim 1 , wherein step 2) is carried out by using toluene, benzene, xylene or a mixture containing two or more of them as a reaction solvent.
7. The process according to claim 1 , wherein the compound of Chemical Formula 4 is obtained by reacting a compound represented by the following Chemical Formula 6 with a compound represented by the following Chemical Formula 7 under basic conditions:
wherein X 1 and X 2 independently represent H or halo.
8. The process according to any one of claims 1 to 7 , wherein X 1 and X 2 independently represent bromine.