201245113 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種製備甲基甘胺酸_N，N_二乙酸三鹼金 屬鹽之水溶液的方法。 【先前技術】 在清潔劑中常用作錯合劑的物質（諸如胺基聚膦酸酯、 聚羧酸酯或胺基聚羧酸酯，例如乙二胺四乙酸（edta))係 僅難以生物降解，或如氮基三乙酸（NTA)般具有毒性。就 NTA而言’已猜測其具有腎致癌性。 具有成本效益的替代物係α_丙胺酸_N，N_二乙酸（甲基甘 胺酸-Ν，Ν·二乙酸下文簡稱為MGDA),其係無毒且可易於 生物降解。 MGDA及其鹽作為錯合劑之用途及其合成法係描述於來 自BASF SE之不同專利申請案（例如DE_A 43 19 935或以_ A 0 745 582)中。 用於製備MGDA之經濟且同時環保的合成途徑係斯特雷 克爾（SUecker)合成法。MGDA之斯特雷克爾合成法係描述 於（例如）WO-A 1994/29421 中。 DE-A 2G 27 972描述甘胺酸（最簡單的未經取代之&祕 叛酸）與曱酿及氫氰酸之斯特雷克爾反應的「酸性」^ 體。在此變體中’甘胺酸形成可以高純度單離之νν_雙 (氛基甲基)甘胺酸，方法的一缺點係必須使用其他酸 以降低ΡΗ及使用相當昂貴之純甘胺酸。在此反應中所形成 之甘胺酸-Ν’Ν-二乙腈係描述為用作交聯劑。提供氮美三 163263.doc 201245113 乙酸之可能的4化作用並非DE_A 20 27 972之標的物。 藉由斯特雷克爾反應使丙胺酸反應產生mgda係首次护 述於WO-A 1994/29421中，其中藉由鱼仆姝田、a 田 /、τ稽田！化作用以高產率獲 得具有高純度之MGDA。 斯特雷克爾反應之「鹼性」變體係以一般形式描述於 (例如）US-A 3 733 355中。然而’其中所列舉之實例顯示 始終出現主要為非所需之氮基三乙酸（NTA)的大量副產 物’此可自至多僅約89%之轉化率推斷出。 EP-A 0 745 582描述一種用於甘胺酸_N，N_二乙酸（諸如 MGDA)的簡單及經濟的合成途徑，其係自成本有效之起始 材料開始，在儘可能無相互聯繫之純化步驟（其中希望同 時具有最高的可能總產率及高產物純度及低NTA含量（儘 可能低於2重量％))之情況下，藉由在pH為〇至丨丨之水性介 質中的斯特雷克爾合成法及隨後的皂化作用而進行，其中 所使用之起始材料係源自甘胺酸衍生物或其前驅物或亞胺 基二乙腈或亞胺基二乙酸之技術合成的原材料（該原材料 尚未經純化，即通常未作為固體經單離或（例如）藉由結晶 作用自次要成份分離），或在該等合成期間所產生之母 液。 【發明内容】 因此，本發明之一目標係提供一種藉由斯特雷克爾合成 法製備MGDA三鹼金屬鹽的進一步改良方法，其特徵尤其 為進一步增加之時空產率及進一步減少之毒性次要組分 (尤其為NTA)的含量（低於〇.1重量％]^丁八，基於4〇重量％漢 I63263.doc 201245113 度之MGDA三鹼金屬鹽水溶液計）。 該目標係藉由一種利用斯特雷克爾合成法製備具有高產 率及純度之MGDA三鹼金屬鹽水溶液的方法而實現，該方 法係自α-丙胺酸水溶液開始，藉由與曱醛及氫氰酸水溶液 反應以提供α-丙胺酸-Ν,Ν-二乙腈，及其與鹼之皂化反應 以提供相應之甲基甘胺酸-Ν，Ν-二乙酸三鹼金属鹽，其 中： -該α·丙胺酸係經部份中和；且 -對用於轉化成α-丙胺酸-Ν，Ν·二乙腈之曱醛及氫氰酸的 添加進行控制’以在任何時間限制該液體反應混合物中 游離氫氰酸之濃度，從而使尤其產生甲醛氰醇之副反應 (包括曱链氰醇之連續反應）及氫氰酸之聚合作用僅在觀 察到對曱基甘胺酸Ν，Ν-二乙酸三鹼金屬鹽之規格要求 (尤其關於氮基三乙酸含量及顏色）之範圍内發生。 在另一實施例中，該目標係藉由一種利用斯特雷克爾合 成法製備曱基甘胺酸-Ν，Ν-二乙酸三鹼金屬鹽之水溶液的 方法來實現，該方法係自α_丙胺酸水溶液開始，藉由在一 個反應單元内與甲醛及氫氰酸反應以提供α_丙胺酸_Ν，Ν_ 一乙賭’及其與驗之皂化反應以提供相應之曱基甘胺酸_ Ν，Ν-二乙酸三鹼金屬鹽的水溶液，其中： -該α-丙胺酸係經部份中和；且 對用於轉化成α-丙胺酸·Ν，Ν•二乙腈之甲醛及氫氰酸的 添加進行控制，以在任何時間限制該水性反應混合物中 游離氫氰酸之濃度，從而使尤其產生甲醛氰醇之副反應 163263.doc 201245113 (包括甲醛氰醇之連續反應）及氫氰酸之聚合作用僅在該 曱基甘胺酸-N，N-二乙酸三鹼金屬鹽之水溶液在該曱基 甘胺酸-N，N-二乙酸三鹼金屬鹽之濃度為40重量％(基於 該曱基甘胺酸-N，N-二乙酸三鹼金屬鹽之水溶液的總重 量計）時具有低於〇.1重量％之氮基三乙酸三鹼金屬鹽含 量的範圍内發生。 本發明者已認識到，可藉由使該胺基酸α-丙胺酸部份中 和自此進料在經歷斯特雷克爾合成之水性溶液中顯著提高 的濃度開始，且由此顯著增加時空產率。與游離胺基酸(X-丙胺酸在室溫下之約18重量％之溶解度（基於溶液之總重量 計）相比，由於部份中和，可實現部份中和之(X-丙胺酸於 水中的濃度為至多40重量％的α-丙胺酸或至多50重量％的 α-丙胺酸（基於水溶液之總重量計），且時空產率相應增 加。 然而，若該斯特雷克爾合成法意欲以僅自部份中和α-丙 胺酸開始之另外已知的方式進行，則較高pH可增加副反應 (尤其係彼等導致毒性NTA形成之副反應）及氫氰酸之非所 需聚合作用（其導致產物形成非所需之深色）的速度。 然而’已令人驚訝地發現，藉由對用於轉化成α_丙胺 酸-Ν，Ν-二乙腈之曱醛及氩氰酸的添加進行控制，以適當 限制該液體反應混合物中游離氫氰酸的濃度，可限制此等 非所需之副反應（意指觀察到MGD Α三鹼金屬鹽之規格要 求’尤其關於NTA含量及顏色）。 通常已知關於MGDA三鹼金屬鹽之NTA含量及顏色的規 I63263.doc 201245113 格要求。 因此，可能致癌之NTA(懷疑具有致癌作用）在約4〇重量 °/〇濃度之MGDA-Na3鹽水溶液中之含量應係低於〇〗重量 %(對照例如「Technical Bulletin-Tril〇n®M Liquid Chelating Agent」，BASF-2009)。201245113 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a process for preparing an aqueous solution of methylglycine-N,N-diacetic acid tribasic metal salt. [Prior Art] Substances commonly used as a binder in detergents (such as amine polyphosphonates, polycarboxylates or amine polycarboxylates such as ethylenediaminetetraacetic acid (edta)) are only difficult to biodegrade. Or as toxic as nitrogen triacetic acid (NTA). As far as NTA is concerned, it has been suspected to have renal carcinogenicity. A cost-effective alternative is alpha-alanine_N,N-diacetic acid (methylglycine-indole, indole diacetic acid, hereinafter referred to as MGDA), which is non-toxic and readily biodegradable. The use of MGDA and its salts as a tweaking agent and its synthesis are described in various patent applications from BASF SE (e.g., DE_A 43 19 935 or _A 0 745 582). The economical and environmentally friendly synthetic route used to prepare MGDA is the SUecker synthesis. The Stryker synthesis method of MGDA is described, for example, in WO-A 1994/29421. DE-A 2G 27 972 describes the "acidic" reaction of glycine (the simplest unsubstituted & retinoic acid) with the brewing and Strecker reaction of hydrocyanic acid. In this variant, 'glycine forms a high purity monolithic νν_bis(alkylmethyl)glycine. A disadvantage of the process is that other acids must be used to reduce hydrazine and to use relatively expensive pure glycine. . The glycine-Ν'Ν-diacetonitrile formed in this reaction is described as being used as a crosslinking agent. Providing Nitrogen III 163263.doc 201245113 The possible chemistry of acetic acid is not the subject of DE_A 20 27 972. The reaction of alanine to produce the mgda line by the Strecker reaction is first described in WO-A 1994/29421, in which the fish servant Putian, a field /, τ quarry! The MGDA is obtained in high yield with high purity. The "alkaline" system of the Strecker reaction is described in general form in, for example, US-A 3 733 355. However, the examples cited therein show that a large number of by-products of nitrogen triacetic acid (NTA), which are mainly undesired, are always present. This can be inferred from a conversion rate of at most only about 89%. EP-A 0 745 582 describes a simple and economical synthesis route for glycine_N,N-diacetic acid (such as MGDA) starting from cost-effective starting materials with as little interlinkage as possible. a purification step in which it is desired to have the highest possible total yield and high product purity and low NTA content (as low as 2% by weight), by means of an aqueous medium having a pH of 〇 to 丨丨The Trekel synthesis and subsequent saponification are carried out, wherein the starting materials used are derived from the raw materials of the glycine derivative or its precursor or the technique of iminodiacetonitrile or imidodiacetic acid ( The starting material has not been purified, i.e., is generally not isolated as a solid or separated from the secondary component by, for example, crystallization, or the mother liquor produced during such synthesis. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a further improved process for the preparation of MGDA tribasic metal salts by Strecker synthesis, which is characterized in particular by a further increase in space-time yield and further reduction of toxicity. The content of the component (especially NTA) (less than 1.1% by weight) ^ 八, based on 4 〇% by weight of Han I63263.doc 201245113 degree of MGDA tribasic metal salt aqueous solution). The object is achieved by a method for preparing an aqueous solution of MGDA tribasic metal salt having high yield and purity by using the Strecker synthesis method, starting from an aqueous solution of α-alanine, by reacting with furfural and hydrocyanide. The aqueous acid solution is reacted to provide α-alanine-hydrazine, hydrazine-diacetonitrile, and its saponification reaction with a base to provide a corresponding methylglycine-indole-triacetic acid tribasic metal salt, wherein: - the α • Alanine is partially neutralized; and – the addition of furfural and hydrocyanic acid for conversion to α-alanine-Ν, Ν·diacetonitrile is controlled to limit the liquid reaction mixture at any time. The concentration of free hydrocyanic acid, so that the side reaction of in particular the formation of formaldehyde cyanohydrin (including the continuous reaction of hydrhydryl cyanohydrin) and the polymerization of hydrocyanic acid are only observed in the bismuth glucosinolate, hydrazine-diacetic acid The specification of the tri-alkali metal salt (especially with respect to the content and color of the nitrogen-based triacetic acid) occurs. In another embodiment, the object is achieved by a method for preparing an aqueous solution of a thioglycine-yttrium-niobetic acid tribasic metal salt by Strecker synthesis, which is from α_ Starting with an aqueous solution of alanine, by reacting with formaldehyde and hydrocyanic acid in a reaction unit to provide α-alanine _ Ν, Ν _ _ _ _ and its saponification reaction to provide the corresponding thioglycine _ An aqueous solution of cerium, cerium-diacetic acid tribasic metal salt, wherein: - the alpha-alanine is partially neutralized; and the formaldehyde and cyanide used for conversion to alpha-alanine, hydrazine, diacetonitrile The addition of the acid is controlled to limit the concentration of free hydrocyanic acid in the aqueous reaction mixture at any time, thereby causing a side reaction of in particular formaldehyde cyanohydrin 163263.doc 201245113 (including continuous reaction of formaldehyde cyanohydrin) and hydrocyanic acid The polymerization is only in the concentration of the thioglycolic acid-N,N-diacetic acid tribasic metal salt in the decylglycine-N,N-diacetic acid tribasic metal salt of 40% by weight (based on The total amount of the aqueous solution of the thioglycine-N,N-diacetic acid tribasic metal salt It occurs within the range meter having an alkali metal content of less than three 〇.1 wt% of the time nitrilotriacetic acid). The inventors have recognized that it is possible to start by neutralizing the amino-α-alanine moiety of the amino acid from a significantly increased concentration in the aqueous solution undergoing Strecker synthesis, and thereby significantly increasing the space-time Yield. Partially neutralized (X-alanine) due to partial neutralization compared to the solubility of free amino acids (X-alanine at room temperature of about 18% by weight based on the total weight of the solution) The concentration in water is up to 40% by weight of α-alanine or up to 50% by weight of α-alanine (based on the total weight of the aqueous solution), and the space-time yield is correspondingly increased. However, if the Strecker synthesis It is intended to be carried out in an otherwise known manner starting from the partial neutralization of alpha-alanine, the higher pH may increase side reactions (especially the side reactions which lead to the formation of toxic NTA) and the undesirable effects of hydrocyanic acid. The rate at which polymerization (which causes the product to form an undesired dark color). However, it has been surprisingly found that by conversion to furfural and argon cyanide for conversion to alpha-alanine-oxime, guanidine-diacetonitrile The addition of acid is controlled to appropriately limit the concentration of free hydrocyanic acid in the liquid reaction mixture, which can limit such undesirable side reactions (meaning that the specification of the MGD ternal metal salt is observed), especially regarding the NTA content. And color). Generally known about MGDA tri alkali metal The content of NTA content and color is required by I63263.doc 201245113. Therefore, the content of NTA (suspected to have carcinogenic effect) which may cause cancer is lower than that of MGDA-Na3 saline solution of about 4〇 weight/〇 concentration. % by weight (controls such as "Technical Bulletin-Tril〇n® M Liquid Chelating Agent", BASF-2009).
同樣地，有關Trilon®M液體之顏色的產物規格通常係已 知，且提供至多350個根據DIN EN 1557之哈贊（Hazen)色 值（對照「Technical Information Trilon®M grades」，BASF 版，2011年4月，第4頁）。 較佳地，將氫氰酸計量添加至液體反應混合物中，以使 游離氫氰酸在該液體反應混合物中之濃度決不大於1〇莫耳 °/〇(基於氫氰酸之添加量計）’較佳決不大於5莫耳％(基於氫 氰酸之添加量計）。 游離氫氰酸在該液體反應混合物中之最大允許濃度亦可 基於所添加之部份中和之α_丙胺酸計，且因此應不超過2〇 莫耳。/〇，較佳1〇莫耳％的游離氫氰酸（基於部份中和之α_丙 胺酸之添加量計）。 部份中和之α-丙胺酸與氫氰酸及甲醛之藉由斯特雷克爾 合成法的反應需要1莫耳α-丙胺酸各對2莫耳氫氰酸及2莫 耳甲醛之化學計量莫耳比。實際上，通常使用195至2 4, 較佳2.0至2.2之ct-丙胺酸對氫氰酸及α•丙胺酸對曱醛的莫 耳比。 ' 在該方法之一較佳實施例中，對用於轉化成卜丙胺酸_ Ν，Μ- 一乙腈之曱醛及氫氰酸的添加進行控制，以在任何時 163263.doc 201245113 間限制游離氫氰酸在該水性反應混合物中的濃度，從而使 ^其產生甲醛氰醇之副反應（包括甲醛氰醇之連續反應）及 虱氰酸之聚合作用僅在該曱基甘胺酸-n，n-二乙酸三鹼金 屬鹽水溶液之哈贊色值小於800，較佳小於6〇〇，特別佳小 於5〇〇的範圍内發生。 在另一較佳實施例中，於另一方法步驟中對甲基甘胺 酉义-N，N-二乙酸三鹼金屬鹽之水溶液進行後漂白，以提供 哈贊色值小於350，較佳小於300之曱基甘胺酸_N,N_二乙 酸三驗金屬鹽的水溶液。 該後漂白（=處理）可藉由化學及/或物理操作來進行。該 化學操作可係氧化性（例如利用過氧化氫或空氣），或還原 (生（例如利用連二亞硫酸納或氫化鈉）。在物理上，該後漂 白可藉由在（例如）活性碳上吸收有色組分來進行。 特別佳地’使用過氧化氫水溶液進行該後漂白。 使用過氧化氫之MGDA三驗金屬鹽水溶液之後漂白可分 階段或連續進行。 因此’舉例而言，可在攪拌式反應器或泵式產物循環中 將該過氧化氫溶液在有效攪拌下計量添加至MGda三鹼金 屬鹽溶液之初始進料中。含量、溫度及停留時間較佳係如 下所述： 通常’極少量過氧化氫滿足特定言之1至5 kg，較佳1至 3 kg過氧化氫（以丨00% h2〇2計算）/1〇〇〇公升4〇%濃度之 MGDA三鹼金屬鹽溶液（相當於約13〇〇 kg)的要求。 較佳地，使用10至50%濃度之過氧化氫水溶液，且以 163263.doc 201245113 3 0%濃度之過氧化氩水溶液（所謂的強雙氧水）特別佳。 以20至80°C之溫度較佳，以30至7(TC之溫度更佳且以 40至65°C之溫度特別佳。較佳的停留時間係1〇至18〇分 鐘，特別佳為15至120分鐘。 在另一實施例中，結晶α-丙胺酸係用作原料（並 或懸浮於水中然後以上述方式部份中和(並= MGDA三驗金厲鹽。 可尤其使用氫氧化鈉或氫氧化鉀或氫氧化鈉與氫氧化鉀 之混合物進行丙胺酸之部份中和。特定而言，α_丙胺酸 之中和作用可進行至40至90%，較佳50至85%，特別佳⑼ 至嶋之中和度。在此，基於水溶液之總重量計’獲得較 佳包含20至50重量％之心丙胺酸，更佳包含乃至扣重量％ 之α-丙胺酸的濃縮水溶液。 在第一方法變體中，使部份中和之α·丙胺酸水溶液與甲 醛及氫氰酸反應，以產生α·丙胺酸_Ν，Ν•二乙腈之水溶 液，該反應之方式係：在與其他兩種反應物（部份中和之 α·丙胺酸及甲酸)相比較遲之操作中，將氫氰酸添加至液 體反應混合物中。 在此’尤其可以分批(半分批)或連續方式操作。 根據第一較佳方法變體’以半分批步驟將部份中和之α_ 丙胺酸水溶液作為初私隹 ’始進枓添加至反應中，且同時計量 添加甲路及氫蒱酿，t 乱文其中與甲搭相比，氫氰酸之計量添加 在時間上係較緩慢。 在第二方法變體中 首先使部份中和之α-丙胺酸與反應 I63263.doc 201245113 所需之全部量甲醛（或其部份量）反應，然後同時計量添加 所得之反應混合物與該反應所需之氫氰酸本身或氫氰酸及 剩餘量之甲路。 在另一較佳方法變體中，該斯特雷克爾合成法係較佳在 兩個或更多個串聯之反應區的級聯中連續進行。 該兩個或更多個串聯反應區可各係單一反應器中之不同 反應區或個別反應器^ 較佳地，在第一反應區内，同時計量添加與反應所需之 全部量甲酸本身或另外與反應所需之部份f氫氰酸分開或 預混合的部份中和之α·丙胺酸。在隨後之反應區内，來自 ν亥第反應區之所得反應混合物與反應所需之全部量氤氰 酸或與剩餘量氫氰酸係同時計量添加。 由斯特雷克爾合成法獲得之α_丙胺醆_Ν，Ν_二乙腈水溶 液的皂化作用係藉由以下方式有利地進行：首先在2〇至8〇 t之溫度下（較佳在30至抑之溫度下），使用氫氧化納溶 液或氫氧化鉀溶液或氫氧化鈉溶液與氫氧化鉀溶液之混合 物^該α·丙胺酸·Ν，Ν_二乙猜水溶液皂化，及然後在州。C 之溫度下4化’以形朗⑽三驗金屬鹽水溶液。在該方 法中在恤度携C下之皂化期間，同時自該反應溶液中 該皂化亦可分階段（半分批）或連續進行 使用α-丙胺酸之[_對映異構體作 在一較佳方法變體中， 為起始材料。 且藉由斯特 α·丙胺酸之L-對映異構體可以低成本獲得， 163263.doc 201245113 雷克爾合成法與氫氰酸及曱醛水溶液反應而產生L_a_丙胺 酸-n，n-二乙腈，且其與鹼之皂化反應產生不僅具有飽和 濃度向於MGDA三驗金屬鹽之D，L-外消旋體之L-對映異構 體’而且亦藉由結晶作用產生易結晶固體的水溶液。 與該外消旋體相比’該具有更高溶解度之l_MGdA三鹼 金屬鹽之優點係可合成、儲存 '出售及運輸更高濃度之溶 液’且因此藉由（例如）高時空產率、低體積合成及儲存容 器、及低運輸或能量成本（例如在喷霧乾燥方法期間）而實 現成本節省。 【實施方式】 下文參考操作實例來更詳細地描述本發明。 對照例1 (半分批；中和度為〇，丙胺酸濃度約丨8% ; HCH〇及hcn 各過量0.03當量） 在30 C下，歷時1小時，將203 g 30%濃度曱醛（2 〇3莫 耳）及54.8 g(2.03莫耳）氫氰酸伴隨冷卻同時添加至含於4〇5 g水中之89 g(l.〇莫耳）a_丙胺酸之溶液（約18%濃度）中。然 後在30°C下後搅拌該混合物1小時。 氰化物總量（即游離未反應之HCN與鍵結於曱醛氛醇内 之氱化物的總和）為〇.32%(分析步驟為電位滴定法）；自游 離HCN之電位滴定測得之HCN轉化率為％% ;阳為丨7。 將245 g 50%濃度之氫氧化鈉溶液（3〇6莫耳）作為初始進 料添加至攪拌式燒瓶内，且在27至36。〇下，歷時丨小時， 伴隨冷卻計量添加上述α·丙胺酸-N，N_二乙腈（ADAN)溶 163263.doc 12 201245113 液。然後，在約3〇t下另外攪拌該混合物6〇分鐘。接著， 將該混合物加熱至95至！…^，且在約3小時内完成皂化。 此產生635 g 39.8%濃度（根據HPLC評估）iMGDA三鈉鹽 溶液，其中NTA_Na3含量為〇.2〇°/。，且哈贊色值為850(其 不符合規格要求），且產率為93.2%。 對照例2 (半分批；如對照例i，但丙胺酸中和度為1〇〇%，丙胺酸濃 度約40%) 將89 g(l，〇莫耳）α_丙胺酸添加至55 g水中。在冷卻之同 時，使用80 g 50%濃度之氫氧化納溶液（1 〇莫耳）完全中和 該混合物（約40%濃度之丙胺酸）；初始pH值為丨3 7。 在約30°C下，於冷卻1小時之同時，計量添加2〇3 g 3〇% 濃度之甲醛（2_03莫耳）及54.8 g(2.03莫耳）氫氰酸。然後， 在3〇°C下後攪拌該混合物1小時。 分析所得之ADAN溶液：氰化物總量2.86%，HCN轉化 率60.5%，最終PH為8.0。 引入165 g 50%》農度之氫氧化納溶液（2 〇6莫耳）β在3〇至 35 C下，將上述ADAN溶液在冷卻i小時的同時添加至其 中。然後’在約30°C下另外攪拌該混合物6〇分鐘。接著， 將該混合物加熱至95至l〇2°C，且歷時約4小時完成息化》 此產生482 g 38_6°/〇濃度（根據HPLC評估）之MGDA三鈉鹽溶 液’其中NTA-Na3含量為5.1〇/〇(不符合規格）。MGDA-Na3 之產率：68.6% ;哈贊色值實質上高於1〇〇〇。 對照例3 163263.doc •13- 201245113 (半分批，如對照例2，但丙胺酸中和度為85%，丙胺酸濃 度約42%) 將89 g(l_〇莫耳）α_丙胺酸添加革55 g水中。在冷卻之同 時，使用68 g 50〇/。濃度之氫氧化鈉溶液（〇 85莫耳）部份中 和該混合物。初始pH值係11.5❶在約3(TC下，於冷卻i小 時之同時’計量添加203 g 30%濃度之曱醛（2.〇3莫耳）及 54·8 g(2.03莫耳）氫氰酸。然後，在3(rc下後攪拌該混合物 1小時。 分析所得之ADAN溶液：氰化物總量0 24%，HCN轉化 率98%，最終pH為4.5。 如在對照例2中所述’使用176.8 g 50%濃度之氫氧化鈉 溶液（2.21莫耳）進行皂化作用》 此產生657 §40.3%濃度之]\4〇〇八-犯3溶液，其中>^八_ Na3含量係0.12%。 就丙胺酸而言’ MGDA-Na3之產率為97.7%，哈贊色值〉 1000。 對照例4 (半分批’如實例1 ’但丙胺酸中和度為65%，丙胺酸濃度 約 3 0%) 將133.5 g( 1.5莫耳）α-丙胺酸添加至230 g水中。在冷卻 之同時，使用78 g 50%濃度之氫氧化鈉溶液（〇 975莫耳）部 份中和該混合物。在40°C下，歷時1 h同時計量添加82 3 呂(3.05莫耳）1^€1^及305 §30。/〇濃度之甲醛（3.〇5莫耳），且在 40°C下後攪拌該混合物1 h。 163263.doc •14· 201245113 分析結果：氰化物總量係0.23%。HCN轉化率係98%。 最終pH係3.9。 類似於對照例2，使用288.8 g 50%濃度之氫氧化鈉溶液 (3.61莫耳）實施皂化作用。 此產生903 g 43.20/〇濃度之MGDA-Na3溶液，其中NTA-Na3含量係0.15%。 MGDA-Na3之產率係96%，哈贊色值係900。 對照例5 (半連續步驟：同時計量添加所有3種組分，使用1 8%濃度 之丙胺酸，中和度為〇) 一般步驟：首先將少量水引入攪拌式反應器中。然後， 在40°C下歷時60分鐘同時計量添加該3種反應物。後反應1 小時。 類似地，就皂化作用而言，首先引入少量NaOH(約 1〇0/。），且在約30至35°C下，歷時1小時，同時計量添加大 量剩餘NaOH及ADAN溶液。後反應及最終皂化作用係在半 分批條件下進行。 MGDA-Na3產率：就丙胺酸而言為92.1% ; NTA-Na3在 40.1。/。濃度之MGDA-Na3溶液中之含量：0.24% ;哈贊色值 為 950。 對照例6 (如對照例5之半連續步驟，但使用30%之丙胺酸濃度，中 和度約70%) MGDA-Na3產率：就丙胺酸而言係92.7% ; NTA-Na3在 163263.doc 201245113 39.9%濃度之]^00八-：^3溶液中之含量：〇_17〇/〇;哈贊色值 >1000 。 對照例7 (連續步驟/攪拌型反應器級聯-無氫氰酸分配） 在於腈階段（Rl、R2及R3)(40°C下）及皂化階段（R4、 R5 ' R6)(40t下）各由3個攪拌型反應器組成的裝置中，連 續製備約40%濃度之MGDA-Na3溶液。然後，在1〇5至11〇 C下’於稅拌型反應器R7中完成該皂化作用及最終之氨汽 提。將HCN、甲醛及丙胺酸溶液（經氫氧化鈉溶液65%部份 中和’丙胺酸含量為30%)添加至R1中，且將氫氧化物溶 液添加至R4中。如對照例4中所述來選擇該等進料之莫耳 比。實施計量添加，以使R1-R2-R3中之停留時間係55至8〇 分鐘R3-R6中之停留時間係2〇〇至280分鐘，及R7令之停留 時間係150-200分鐘。通常，該產物之NTA_Na3含量係〇25 至0.40°/。’且哈赞色值係yooo。 MGDA-Na3產率：就丙胺酸而言係92%至93%。 實例1 (半分批’如對照例4 ’但比HCN更快速地計量添加曱醛） 與對照例4相比’歷時30分鐘計量添加曱醛，且歷時6〇 分鐘計量添加HCN » MGDA_Na3產率：就丙胺酸而言係98.1% ; NTA-Na3在 40.4%濃度之MGDA-Na3溶液中的含量：〇.〇6°/0 ;哈贊色值 為 320。 實例2 163263.doc 16* 201245113 (包括後漂白） 在約60°C下，伴隨強力攪拌，將10 g 3〇%濃度之過氣化 氫溶液歷時15分鐘計量添加至根據實例丨所獲得之溶液 中。然後，在60 C下另外攪拌該混合物約3〇分鐘。所得☆ 液具有180之哈贊色值。 ' 實例3 (半分批’丙胺酸濃度30%，中和度約70%) 將89 g(l_0莫耳）α-丙胺酸添加至15〇 g水中。在冷卻之同 時，使用56 g 50%濃度之氫氧化鈉溶液（〇7莫耳）部份中和 該混合物。 在40°C下’歷時60分鐘計量添加203 g 30%濃度之甲酸 (2.03莫耳）’且同時在約40 °C下，歷時90分鐘計量添加 54.8 g(2.03莫耳）氫氰酸。 然後，在40°C下後攪拌該混合物30分鐘。 所得AD AN溶液之分析：氰化物總量為〇·29%，HCN轉 化率為99%，最終pH為4.1。 引入189 g 50%濃度之氫氧化鈉溶液（2.36莫耳）。在45至 5 0 C下，將上述AD AN溶液歷時1小時添加至此氫氧化納溶 液中。然後在50°C下另外攪拌該混合物60分鐘。 接著，在95至1 02°C下，歷時約3小時完成皂化作用及氨 蒸顧。 此產生665 g約39.5%濃度之河00八-\33溶液。 產率：97.0% ; NTA-Na3含量：0.08% ;哈贊色值： 340。 163263.doc 201245113 實例4 (如對照例4之半連續步驟’但歷時3〇分鐘更快速地計量添 加丙胺酸及甲醛，氫氰酸添加歷時6〇分鐘） 97·6% ; 40.3% 濃度之 :0.03% ;哈贊色值： 最佳結果.M G D A - N a 3產率： ADA-Na3溶液中的NTA-Na3含量 330 » 實例5 在實例2之條件下漂白根據實例4獲得的溶液。此形成 150之哈赞色值。 實例6 (如對照例4之半連續步驟，但其中分開3〇〇/。氫氰酸） 在4(TC下’歷時6〇分鐘’同時計量添加中和度為7〇%之 約规濃度的丙胺酸、甲酿及僅為總量之7〇%之氫氰酸。 然後，在無後反應之情況下釋放所得之反應混合物，且立 即與剩餘30%之氫氰酸同時計量添加（歷時6〇分鐘）。在扣 °C下’另外搅拌該混合物30分鐘。 如對照例5中所述來進行皂化作用。 MGDA-Na3產率：96.6%; NTA_Na3含量：〇 〇7%;哈贊 色值：370。 實例7 (如實例6之半連續步驟，丙胺酸濃度為3〇%，中和度約 70°/。，但分開50%氬氰酸） MGDA-Na3產率.97.3%; 39.9%濃度之1^0八抱3溶液 中的NTA-Na3含量：0.050/。；哈贊色值：32〇。 I63263.doc 201245113 實例8 (連續步驟/攪拌型反應器級聯，其中分配氫氰酸） 如對照例7中所述來連續製備約4〇%濃度之MGDA-Na3溶 液’然而’其中亦計量添加HCN至R2中，且將HCN之添加 量以4:1之比例分配在汉丨與以之間。該產物通常具有<〇 1〇/〇 之NTA-Na3含量及450至650之哈贊色值。 MGDA-Na3產率：就丙胺酸而言為97-98.5%。 實例9 (包括後漂白） 然後藉由在停留時間容器内，於4〇至50 °C下計量添加 30%濃度之過氧化氫（約5公升/1 m3溶液）及完成反應，以在 停留時間部份内漂白實例8中所得之溶液。 此通常產生<300之哈贊色值。 實例10 : 約50重量％濃度之L-MGDA-Na3溶液的製法 (類似於實例8 ’但使用L-α-丙胺酸作為丙胺酸源） 在於95至102°C下皂化之最終階段内，蒸餾出所形成之 氨及足夠水’以最終形成約50重量。/〇濃度的L-MGDA-Na3 鹽溶液。 L-MGDA-Na3產率：基於L-丙胺酸計係97.0%。NTA-Na3 含量：0.08%。哈贊色值係270。 因此獲得NTA殘留含量極低之淺色高濃度（5〇重量％濃 度）錯合劑溶液。 163263.doc -19-Similarly, the product specifications for the color of the Trilon® M liquid are generally known and provide up to 350 Hazen colour values according to DIN EN 1557 (cf. "Technical Information Trilon® M grades", BASF edition, 2011 April, page 4). Preferably, hydrocyanic acid is metered into the liquid reaction mixture such that the concentration of free hydrocyanic acid in the liquid reaction mixture is never greater than 1 mole % / Torr (based on the amount of hydrocyanic acid added) 'It is preferably not more than 5 mol% based on the amount of hydrocyanic acid added. The maximum allowable concentration of free hydrocyanic acid in the liquid reaction mixture can also be based on the added portion of the neutralized alpha-alanine, and therefore should not exceed 2 moles. /〇, preferably 1% by mole of free hydrocyanic acid (based on the amount of partially neutralized α-alanine added). The partial neutralization of α-alanine with hydrocyanic acid and formaldehyde by Strecker synthesis requires 1 mol of α-alanine to 2 mol of hydrogen cyanide and 2 mol of formaldehyde stoichiometry Moerby. In practice, the molar ratio of cp-alanine to hydroxycyanate and a-alanine to furfural is usually used from 195 to 24, preferably from 2.0 to 2.2. In a preferred embodiment of the method, the addition of furfural and hydrocyanic acid for conversion to amphetamine Μ, Μ-acetonitrile is controlled to limit free at any time 163263.doc 201245113 The concentration of hydrocyanic acid in the aqueous reaction mixture, such that the side reaction of the production of formaldehyde cyanohydrin (including the continuous reaction of formaldehyde cyanohydrin) and the polymerization of phthalocyanine are only in the thioglycine-n, The Hazan color value of the n-diacetic acid tribasic metal salt aqueous solution occurs in a range of less than 800, preferably less than 6 Å, particularly preferably less than 5 Å. In another preferred embodiment, the aqueous solution of the methylglycine-N,N-diacetic acid tribasic metal salt is post-bleached in another method step to provide a Hazan color value of less than 350, preferably An aqueous solution of less than 300 decylglycine _N,N-diacetic acid three metal salts. This post-bleaching (=treatment) can be carried out by chemical and/or physical manipulation. The chemical operation may be oxidative (eg, using hydrogen peroxide or air), or reduced (eg, using sodium dithionite or sodium hydride). Physically, the post-bleaching may be by, for example, activated carbon. The absorption of the colored component is carried out. It is particularly preferred to use the aqueous hydrogen peroxide solution for the subsequent bleaching. The bleaching of the aqueous solution of MGDA triple metal salt using hydrogen peroxide can be carried out in stages or continuously. Thus, for example, The hydrogen peroxide solution is metered into the initial charge of the MGda tri-alkali metal salt solution under agitation in a stirred reactor or pump product cycle. The content, temperature and residence time are preferably as follows: A very small amount of hydrogen peroxide meets the specific 1 to 5 kg, preferably 1 to 3 kg of hydrogen peroxide (calculated as 丨00% h2〇2) / 1 〇〇〇 liter of 4% by weight of MGDA tribasic metal salt solution (corresponding to about 13 〇〇kg). Preferably, a 10 to 50% aqueous solution of hydrogen peroxide is used, and an aqueous solution of argon peroxide (so-called strong hydrogen peroxide) having a concentration of 163263.doc 201245113 30% is used. Good. Take 20 The temperature to 80 ° C is preferably from 30 to 7 (the temperature of TC is more preferably and the temperature is preferably from 40 to 65 ° C. The preferred residence time is from 1 to 18 minutes, particularly preferably from 15 to 120. In another embodiment, crystalline α-alanine is used as a raw material (and or suspended in water and then partially neutralized in the above manner (and = MGDA three gold salts. In particular, sodium hydroxide or hydrogen can be used) Potassium oxide or a mixture of sodium hydroxide and potassium hydroxide for partial neutralization of alanine. In particular, the neutralization of α-alanine can be carried out to 40 to 90%, preferably 50 to 85%, particularly preferably (9) To the degree of neutralization. Here, based on the total weight of the aqueous solution, a concentrated aqueous solution of preferably comprises from 20 to 50% by weight of cardiac alanine, more preferably or even by weight of α-alanine. In a method variant, a partially neutralized aqueous solution of α-alanine is reacted with formaldehyde and hydrocyanic acid to produce an aqueous solution of α·alanine Ν, Ν•diacetonitrile, in a manner similar to The two reactants (partially neutralized α·alanine and formic acid) are later added to the hydrogen cyanate Addition to the liquid reaction mixture. In particular, it can be operated in batch (semi-batch) or continuous mode. According to the first preferred method variant, the partially neutralized α-alanine aqueous solution is used as a preliminary step in a semi-batch step. 'Initial enthalpy is added to the reaction, and at the same time, the addition of the road and the hydrogen sputum are measured. In the chaos, the metered addition of hydrocyanic acid is slower in time than the methadone. In the second method variant, first Partially neutralizing the alpha-alanine with the total amount of formaldehyde (or a portion thereof) required for the reaction I63263.doc 201245113, and then simultaneously metering the resulting reaction mixture with the hydrocyanic acid itself required for the reaction or Hydrogen cyanide and the remaining amount of the road. In another preferred process variant, the Strecker synthesis process is preferably carried out continuously in a cascade of two or more reaction zones in series. The two or more series reaction zones may each be a different reaction zone in a single reactor or an individual reactor. Preferably, in the first reaction zone, the entire amount of formic acid required for the reaction itself is metered in or Further, the partially neutralized α-alanine is separated or premixed with the portion of the reaction required for the reaction. In the subsequent reaction zone, the resulting reaction mixture from the νhai reaction zone is metered in simultaneously with the total amount of decanoic acid required for the reaction or with the remaining amount of hydrocyanic acid. The saponification of the aqueous solution of α_propylamine 醆_Ν, Ν_diacetonitrile obtained by Strecker synthesis is advantageously carried out by first at a temperature of from 2 Torr to 8 Torr (preferably at 30 to At a temperature, a sodium hydroxide solution or a potassium hydroxide solution or a mixture of a sodium hydroxide solution and a potassium hydroxide solution is used. The α-alanine·Ν, Ν_二乙猜 aqueous solution is saponified, and then in the state. At the temperature of C, the aqueous solution of the metal salt was formed by a three-dimensional test. In the method, during the saponification under the carrier C, the saponification from the reaction solution may also be carried out in stages (half batch) or continuously using the [-enantiomer of α-alanine as a comparison In the preferred method variant, it is the starting material. And can be obtained at low cost by the L-enantiomer of αα·alanine, 163263.doc 201245113 The Raikkelne synthesis method reacts with hydrocyanic acid and aqueous furfural to produce L_a_alanine-n,n- Diacetonitrile, and its saponification reaction with a base produces not only a saturated concentration of the D-L-enantiomer of the D, L-racemate of the MGDA triple metal salt, but also a crystallized solid by crystallization Aqueous solution. The advantage of the l_MGdA tri-alkali metal salt with higher solubility compared to the racemate is that it can synthesize, store 'sell and transport higher concentrations of solution' and thus by, for example, high space-time yield, low Cost savings are achieved by volumetric synthesis and storage of containers, and low transportation or energy costs (eg, during spray drying processes). [Embodiment] Hereinafter, the present invention will be described in more detail with reference to operation examples. Comparative Example 1 (half batch; neutralization is 〇, alanine concentration is about 8%; HCH 〇 and hcn are each 0.03 equivalent). At 30 C, 203 g of 30% concentration of furfural (2 〇) over 1 hour. 3 mol) and 54.8 g (2.03 mol) of hydrocyanic acid were added to a solution (about 18% concentration) of 89 g (l. mol) a-alanine contained in 4 g of 5 g of water with cooling. . The mixture was then stirred at 30 ° C for 1 hour. The total amount of cyanide (ie, the sum of free unreacted HCN and the telluride bonded to the furfural alcohol) is 3232% (analytical step is potentiometric titration); HCN measured by potentiometric titration of free HCN The conversion rate is %%; the yang is 丨7. 245 g of a 50% strength sodium hydroxide solution (3 〇 6 mol) was added as an initial charge to the stirred flask at 27 to 36. The above α·alanine-N,N-diacetonitrile (ADAN) dissolved 163263.doc 12 201245113 solution was added to the underarm for a period of time. The mixture was then stirred for an additional 6 minutes at about 3 Torr. Next, heat the mixture to 95 to! ...^, and saponification is completed in about 3 hours. This gave a concentration of 635 g 39.8% (according to HPLC) of the iMGDA trisodium salt solution, wherein the NTA_Na3 content was 〇.2 〇 ° /. And the Hazan color value is 850 (which does not meet the specifications), and the yield is 93.2%. Comparative Example 2 (half batch; as in Comparative Example i, but the degree of neutralization of alanine was 1%, the concentration of alanine was about 40%) 89 g (l, 〇mol) α-alanine was added to 55 g of water . While cooling, the mixture was completely neutralized (about 40% alanine) using 80 g of a 50% sodium hydroxide solution (1 Torr); the initial pH was 丨37. At a temperature of about 30 ° C, 2 〇 3 g of a concentration of formaldehyde (2_03 mol) and 54.8 g (2.03 mol) of hydrocyanic acid were metered in while cooling for 1 hour. Then, the mixture was stirred at 3 ° C for 1 hour. The obtained ADAN solution was analyzed: the total amount of cyanide was 2.86%, the conversion of HCN was 60.5%, and the final pH was 8.0. A 165 g 50% "Non-salt sodium hydroxide solution (2 〇 6 mol) β was introduced at 3 Torr to 35 C, and the above ADAN solution was added thereto while cooling for 1 hour. The mixture was then stirred for an additional 6 minutes at about 30 °C. Next, the mixture was heated to 95 to 10 ° C and completed for about 4 hours. This yielded 482 g 38_6 ° / 〇 concentration (according to HPLC evaluation) of MGDA trisodium salt solution 'where NTA-Na3 content It is 5.1〇/〇 (not in compliance with specifications). The yield of MGDA-Na3: 68.6%; the Hazan color value is substantially higher than 1 〇〇〇. Comparative Example 3 163263.doc •13- 201245113 (semi-batch, as in Comparative Example 2, but the degree of neutralization of alanine is 85%, the concentration of alanine is about 42%) 89 g (l_〇莫) α-alanine Add leather to 55 g of water. At the same time of cooling, use 68 g 50 〇 /. The mixture was neutralized in a portion of sodium hydroxide solution (〇 85 mol). The initial pH value is 11.5 ❶ at about 3 (at TC, while cooling for i hours), measurably add 203 g of 30% strength furfural (2. 〇 3 mol) and 54·8 g (2.03 mol) hydrocyanide. Then, the mixture was stirred for 1 hour at 3 (rc). The obtained ADAN solution was analyzed: total amount of cyanide was 0 24%, HCN conversion was 98%, and final pH was 4.5. As described in Comparative Example 2 Saponification was carried out using 176.8 g of a 50% strength sodium hydroxide solution (2.21 mol). This yielded a 657 § 40.3% concentration of \4 〇〇 八 -3 solution, wherein >^8_Na3 content was 0.12% For the case of alanine, the yield of 'MGDA-Na3 was 97.7%, Hazan color value> 1000. Comparative Example 4 (half batch 'as in Example 1' but the degree of neutralization of alanine was 65%, and the concentration of alanine was about 3 0%) 133.5 g (1.5 moles) of a-alanine was added to 230 g of water. While cooling, the mixture was partially neutralized with 78 g of a 50% strength sodium hydroxide solution (〇975 mole). At 40 ° C, for a period of 1 h, add 82 3 L (3.05 mol) 1 ^ € 1 ^ and 305 § 30. / 〇 concentration of formaldehyde (3. 〇 5 Mo), and at 40 ° C After stirring the mixture for 1 h 163263.doc •14· 201245113 Analysis results: The total amount of cyanide was 0.23%. The conversion rate of HCN was 98%. The final pH was 3.9. Similar to Control 2, 288.8 g of 50% sodium hydroxide solution (3.61) was used. The saponification was carried out. This produced a 903 g 43.20/〇 concentration of MGDA-Na3 solution, wherein the NTA-Na3 content was 0.15%. The yield of MGDA-Na3 was 96%, and the Hazan color value was 900. Comparative Example 5 (Semi-continuous step: simultaneously metering all 3 components, using a concentration of 18% alanine, the degree of neutralization is 〇) General procedure: first introduce a small amount of water into the stirred reactor. Then, at 40 ° C The three reactants were metered in simultaneously over 60 minutes. The reaction was followed for 1 hour. Similarly, in terms of saponification, a small amount of NaOH (about 1 Torr) was introduced first, and at about 30 to 35 ° C for a duration of At the same time, a large amount of residual NaOH and ADAN solution were metered in. The post reaction and final saponification were carried out under semi-batch conditions. MGDA-Na3 yield: 92.1% for alanine; NTA-Na3 at 40.1%. The content of the concentration in the MGDA-Na3 solution was 0.24%; the Hazan color value was 950. Comparative Example 6 (Like the semi-continuous step of Comparative Example 5, but using a 30% alanine concentration, the degree of neutralization is about 70%) MGDA-Na3 yield: 92.7% for alanine; NTA-Na3 at 163263.doc 201245113 39.9 % concentration] ^00 eight-: ^3 content in the solution: 〇 _17 〇 / 〇; Hazan color value > 1000. Comparative Example 7 (continuous step / stirred reactor cascade - no hydrocyanic acid partitioning) in the nitrile stage (Rl, R2 and R3) (at 40 ° C) and the saponification stage (R4, R5 'R6) (at 40t) In a device consisting of three stirred reactors, a solution of about 40% concentration of MGDA-Na3 was continuously prepared. This saponification and final ammonia stripping are then carried out in a tax-mixed reactor R7 at 1〇5 to 11〇C. A solution of HCN, formaldehyde and alanine (neutralized by a 65% portion of sodium hydroxide solution ' 30% alanine content) was added to R1, and a hydroxide solution was added to R4. The molar ratios of the feeds were selected as described in Comparative Example 4. The metering is carried out so that the residence time in R1-R2-R3 is 55 to 8 minutes, the residence time in R3-R6 is 2 to 280 minutes, and the residence time in R7 is 150 to 200 minutes. Typically, the product has a NTA_Na3 content of 〇25 to 0.40 °/. 'And the Hazan color value is yooo. MGDA-Na3 yield: 92% to 93% with respect to alanine. Example 1 (semi-batch 'as in Comparative Example 4' but with the addition of furfural faster than HCN) Compared to Comparative Example 4, 'furfural was metered over for 30 minutes and HCN was metered in over 6 minutes. » MGDA_Na3 Yield: For the case of alanine, it is 98.1%; the content of NTA-Na3 in the 40.4% concentration of MGDA-Na3 solution: 〇.〇6°/0; Hazan color value is 320. Example 2 163263.doc 16* 201245113 (including post-bleaching) 10 g of a 3% by weight solution of hydrogen peroxide over a period of 15 minutes was added to the solution obtained according to the example at about 60 ° C with vigorous stirring. in. The mixture was then stirred at 60 C for about 3 minutes. The resulting ☆ liquid has a Hazan color value of 180. 'Example 3 (half batch 'alanine concentration 30%, neutralization degree about 70%) 89 g (l_0 mole) of a-alanine was added to 15 〇 g of water. While cooling, the mixture was partially neutralized using 56 g of a 50% strength sodium hydroxide solution (〇7 mol). 203 g of 30% strength formic acid (2.03 moles) was metered in at 60 ° C for 60 minutes while simultaneously adding 54.8 g (2.03 moles) of hydrocyanic acid at about 40 ° C over a period of 90 minutes. Then, the mixture was stirred at 40 ° C for 30 minutes. Analysis of the obtained AD AN solution: the total amount of cyanide was 〇·29%, the HCN conversion rate was 99%, and the final pH was 4.1. 189 g of 50% strength sodium hydroxide solution (2.36 mol) was introduced. The above AD AN solution was added to this sodium hydroxide solution over a period of 1 hour at 45 to 50 °C. The mixture was then stirred at 50 ° C for an additional 60 minutes. Next, saponification and ammonia distillation were completed at about 95 to 102 ° C for about 3 hours. This yielded 665 g of a 39.5% concentration of the river 00-8-\33 solution. Yield: 97.0%; NTA-Na3 content: 0.08%; Hazan color value: 340. 163263.doc 201245113 Example 4 (as in the semi-continuous step of Comparative Example 4, but with the addition of alanine and formaldehyde more rapidly over 3 minutes, the addition of hydrocyanic acid lasted 6 minutes) 97.6%; 40.3% concentration: 0.03%; Hazan color value: Best result. MGDA - N a 3 yield: NTA-Na3 content in ADA-Na3 solution 330 » Example 5 The solution obtained according to Example 4 was bleached under the conditions of Example 2. This forms a Hazan color value of 150. Example 6 (as in the semi-continuous step of Comparative Example 4, but in which 3 〇〇/. hydrocyanic acid was separated) at 4 (TC lasts for 6 〇 minutes) while metering the neutralization degree to a concentration of 7〇% Alanine, brewing and only a total of 7% by weight of hydrocyanic acid. Then, the resulting reaction mixture is released without post-reaction and immediately metered with the remaining 30% hydrocyanic acid (duration 6) 〇min). The mixture was stirred for another 30 minutes at a temperature of ° C. Saponification was carried out as described in Comparative Example 5. MGDA-Na3 yield: 96.6%; NTA_Na3 content: 〇〇7%; Hazan color value : 370. Example 7 (as in the semi-continuous step of Example 6, the concentration of alanine is 3〇%, the degree of neutralization is about 70°/., but 50% argonic acid is separated) MGDA-Na3 yield: 97.3%; 39.9% The content of NTA-Na3 in the solution of the concentration of 1^0 八抱3: 0.050/.; Hazan color value: 32 〇. I63263.doc 201245113 Example 8 (continuous step/stirred reactor cascade in which hydrocyanic acid is partitioned Continually prepare a concentration of MGDA-Na3 solution of about 4% by weight as described in Comparative Example 7 'however' in which HCN to R2 is also metered in, and HCN is added. It is distributed between the sorghum and the sorghum in a ratio of 4:1. The product usually has a NTA-Na3 content of <〇1〇/〇 and a Hazan color value of 450 to 650. MGDA-Na3 yield: on alanine In the case of 97-98.5%. Example 9 (including post-bleaching) Then 30% concentration of hydrogen peroxide (about 5 liters / 1 m3 solution) was metered in at a residence time container at 4 to 50 °C. And the reaction was completed to bleach the solution obtained in Example 8 in the residence time portion. This usually yielded a Hazan color value of < 300. Example 10: Preparation of a solution of about 50% by weight of L-MGDA-Na3 solution (similar In Example 8 'but using L-α-alanine as the source of alanine), in the final stage of saponification at 95 to 102 ° C, the formed ammonia and enough water were distilled off to finally form about 50% by weight. L-MGDA-Na3 salt solution L-MGDA-Na3 yield: 97.0% based on L-alanine. NTA-Na3 content: 0.08%. Hazan color value is 270. Therefore, the NTA residue content is extremely low. High concentration (5 〇 wt% concentration) solution of the wrong agent. 163263.doc -19-