Method of producing a crystalline form of sodium 2-[(4S)-8-fluoro-2-[4-(3- methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-4H-quinazoline-4-yl]acetate trihydrate

A method of producing a crystalline form of sodium 2-[(4S)-8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-4H-quinazolin-yl]acetate trihydrate of formula (I)

• the method comprising the steps:
• Step 1) providing a solution of 2-[(4S)-8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-4H-quinazolin-4-yl]acetic acid in a mixture of a (C1-C6) alkyl acetate and a (C1-C6) dialkyl ether, wherein the molar ratio of (C1-C6) alkyl acetate:(C1-C6) dialkyl ether is from 1:1 to 1:3 in a concentration range of from 0.3 M to 0.7 M;
• Step 2) adding 1.0 to 2.0 mole equivalents of an aqueous sodium hydroxide solution based on the 2-[(4S)-8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-4H-quinazolin-4-yl]acetic acid content to the solution resulting from step 1 to provide a mixture;
• Step 3) stirring the mixture resulting from step 2 for at least 30 minutes at a temperature in the range of from 30° C. to 60° C. to obtain a suspension containing a solid compound;
• Step 4) separating the solid compound from the suspension resulting from step 3;
• and
• Step 5) drying the solid compound resulting from step 4 at a temperature in the range of from 30° C. to 60° C. for at least one hour to obtain crystalline sodium 2-[(4S)-8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-4H-quinazolin-4-yl]acetate trihydrate.