US 9,115,177 B2  4  3  In the aforementioned preparation method, the cation in the  weak base solution is sodium ion; pKA value of the conjugate  acid corresponding to the weak base is 4-11, preferably 5-8.  In the aforementioned preparation method, the weak base  is organic weak base solution, inorganic weak base solution,  or combination thereof. The organic weak base is selected  from the group consisting of disodium hydrogen citrate,  sodium citrate, sodium acetate, sodium propionate, sodium  butyrate,  sodium isobutyrate,  sodium tartrate,  sodium  oxalate, sodium benzoate, sodium sorbate, sodium malate,  monosodium succinate, disodium succinate and combina› tions thereof; preferably, the organic weak base is selected  from the group consisting of disodium hydrogen citrate,  sodium citrate, sodium acetate and combinations thereof. The  inorganic weak base is selected from the group consisting of  sodium bicarbonate, sodium carbonate, disodium hydrogen  phosphate, sodium borate, sodium sulfite, sodium hydrosul› fide and combinations thereof; preferably, the inorganic weak  base is sodium bicarbonate.  In the aforementioned preparation method, the pH value of  the solution obtained from mixing the weak base solution  with the water solution containing the compound of formula  I is 4.0-7.0, preferably 4.0-6.0, most preferably 4.5-5.5.  In the aforementioned preparation method, the pH value of  the solution obtained from mixing the weak base solution  with the mixture solution of water and organic solvent(s)  containing the compound of formula I is 4.0-7.0, preferably  4.0-6.0, most preferably 4.5-5.5.  In the aforesaid preparation method, the concentration of  the weak base solution is 0.001-1 mol/L; preferably, 0.01-0.5  mol/L.  In the aforesaid preparation method, the organic solvent is  selected from alcohols or acetonitrile, preferably a Cl-C4  alcohol, most preferably selected from the group consisting  of methanol, ethanol, isopropanol, n-propanol, n-butanol,  sec-butanol, t-butanol and combinations thereof.  In another embodiment, a preparation method for the com› pound of formula II is provided in the Invention, comprising  the following steps:  at room temperature, adding the weak base solution to the  water solution containing the compound of Formula I or the  mixture solution of water and organic solvent(s) containing  the compound of Formula I, adjusting the pH value of the  obtained solution, thereby obtaining the compound of For- mula II; and said addition is performed slowly with stirring.  Thus, the Invention provided a preparation method for  micafungin sodium so as to obtain micafungin sodium of high  purity.  Retention Time  Area  Height  Percentage of Area  13.112  21149  1395  0.06  16.581  61878  3000  0.18  17.318  21882  1309  0.06  18.479  33290939  1423115  98.01  19.365  38294  2451  0.11  20.599  289113  6553  0.85  22.127  28987  1280  0.09  23.124  17974  976  0.05  23.791  140287  6104  0.41  25.357  15057  439  0.04  26.618  9618  399  0.03  28.392  31413  1013  0.09  Retention Time  Area  Height  Percentage of Area  7.814  20127  1462  0.04  8.809  7857  724  0.01  9.453  16198  1238  0.03  10.600  4883  420  0.01  12.114  7499  483  0.01  13.108  48805  2465  0.09  14.814  17647  893  0.03  16.587  111648  5015  0.21  17.322  42997  2356  0.08  18.478  51279846  2121252  97.67  19.368  64987  4085  0.12  20.076  443712  10219  0.85  22.111  52715  2171  0.10  23.129  34128  1790  0.06  23.794  253956  10958  0.48  25.375  25571  756  0.05  26.637  23028  707  0.04  28.381  49128  1492  0.09  Retention Time  16.492  18.227  20.471  Area  28624  20543002  69682  Height  1585  963168  3906  Percentage of Area  0.14  99.52  0.34  Retention Time  16.492  18.227  20.471  Area  31807  20816865  63295  Height  1659  967335  3710  Percentage of Area  0.15  99.55  0.30  DESCRIPTION OF FIGURES  FIG.1  is the HPLC chromatogram of formula I compound  in Example 1, wherein parameters of the related peaks, such  as Retention Time and areas thereof are listed in the following  table.  FIG.  2  is the HPLC chromatogram of formula II compound  prepared in Comparative Example 2, wherein parameters of  the related peaks, such as Retention Time and areas thereof  are listed in the following table.  FIG.  3  is the HPLC chromatogram of formula II compound  prepared in Comparative Example 2, wherein parameters of  the related peaks, such as Retention Time and areas thereof  are listed in the following table.  FIG.  4  is the HPLC chromatogram of formula II compound  prepared in Example 4, wherein parameters of the related  peaks, such as Retention Time and areas thereof are listed in  the following table.  FIG.  5  is the HPLC chromatogram of formula II compound  prepared in Example 5, wherein parameters of the related  peaks, such as Retention Time and areas thereof are listed in  the following table.  FIG.  6  illustrates the pH value curve of titrating strong acid  (hydrochloric acid) with strong base (NaOH solution).  FIG.  7  illustrates the pH value curve of titrating micafungin  solution with 0.1 M solution of sodium bicarbonate.  Retention Time  Area  Height  Percentage of Area  16.490  26352  1220  0.20  17.214  8971  547  0.07  18.227  13162110  614407  99.17  19.255  8117  545  0.06  20.468  56926  2842  0.43  23.620  9839  512  0.07 