A process for preparing a herbicidally active carboxylic acid salt is disclosed, the process comprising the steps of: i) combining a carboxylic acid with a high-boiling, water-immiscible organic solvent to obtain a solution or slurry； ii) treating the solution or slurry produced in step (i) with a base to form a carboxylic acid salt； iii) removing solvent from the mixture produced in step (ii) to obtain a carboxylic acid salt cake； and v) drying the cake obtained in step (iii). The process is particularly suitable for preparing a salt of dicamba. A process for preparing dicamba-sodium comprises: (1)dissolving a carboxylic acid consisting essentially of dicamba in a high-boiling water-immiscible inert organic solvent to get a solution or slurry； (2)treating the dicamba solution or slurry in Step 1 with a base selected from sodium hydroxide, sodium bicarbonate and mixtureS thereof, at a molar ratio of 1:0.97±0.6% to form dicamba-sodium； (3)centrifuging the reaction mixture in Step 2 to obtain dicamba-sodium salt cake； and (4)drying the dicamba-sodium cake obtained in Step 3 to get a dry dicamba-sodium consistently having a pH value between about 7 and 10 when dissolved in water.公開一種製備具有除草活性的羧酸鹽的方法，該方法包括以下步驟：i)將羧酸與高沸點、不與水混溶的有機溶劑混合，得到溶液或漿料；ii)在步驟(i)生成的溶液或漿料中加入一種鹼形成羧酸鹽；iii)除去步驟(ii)產生的混合物中的溶劑，得到羧酸鹽餅；及v)烘乾步驟(iii)得到的餅。該方法尤其適合製備麥草畏(dicamba)鹽。一種製備麥草畏-鈉的方法包括：(1)將基本由麥草畏組成的羧酸溶解於高沸點、不與水混溶的惰性有機溶劑中，得到溶液或漿料；(2)在氫氧化鈉、碳酸氫鈉及彼等之混合物中選擇一種鹼，按照莫耳比1：0.97±0.6%加入步驟1的麥草畏溶液或漿料，形成麥草畏-鈉；(3)將步驟2中的反應混合物離心，得到麥草畏-鈉鹽餅；及(4)烘乾步驟3得到的麥草畏-鈉餅，得到乾燥的麥草畏-鈉，使其溶於水後的pH值始終介於7到10左右。
