Process for the production of a compound comprising potassium phosphite comprising the steps of (a) reacting carboxylic acid of the formula R-(C(=O)OH)nwith phosphorous trichloride (PCl3) towards a mixture comprising phosphorous acid (H3PO3) and acid chloride of the formula R-(C(=O)Cl)n； wherein R is a linear or branched alkyl or alkanediyl group with 1-20 carbon atoms and n is 1 or 2, (b) subjecting said mixture to a separation step, thereby obtaining (i) a fraction comprising crude phosphorous acid (H3PO3) and (ii) a fraction comprising acid chloride, (c) combining water, a potassium compound selected from KOH, KHCO3and K2CO3, and the fraction comprising crude phosphorous acid, thereby forming an aqueous solution comprising potassium phosphite, and (d) removing organic compounds from said aqueous solution.本發明係關於製造包含亞磷酸鉀之化合物之方法，其包含以下步驟：(a) 使式R-(C(=O)OH)n之羧酸與三氯化磷(PCl3)反應產生包含亞磷酸(H3PO3)及式R-(C(=O)Cl)n之醯氯之混合物；其中R係具有1-20個碳原子之直鏈或具支鏈烷基或烷二基且n為1或2，(b) 使該混合物經歷分離步驟，由此獲得(i)包含粗製亞磷酸(H3PO3)之流份及(ii)包含醯氯之流份，(c) 將水、選自KOH、KHCO3及K2CO3之鉀化合物及該包含粗製亞磷酸之流份組合，由此形成包含亞磷酸鉀之水溶液，及(d) 自該水溶液去除有機化合物。
