Methylamine processes

Mitsubishi smelting process, 16 146 Mitsui Chemical methylamine process,... 

The Nitto Chemical Methylamines Process, PEP Review No. 89-3-4, SRI Consulting, process-economics.com/reviews/89-3-4.htm, February 1991. 

Figure 22.24 shows a typical methylamines process diagram.117 The raw material and utility use are summarized in Table 22.25.17... 

This product shape selectivity of the zeolites of adjusting their acidity and pore openings composition of the product mixture according to commercial requirements, than in the case of the classical reaction on AI2O3 [52, 53]. A commercial methylamines plant (approx. 45 000 t/y) based on zeolite-type catalsts has been in operation at Nitto Chemicals since 1984 [54]. SRI-International evaluates, that the Nitto Chemical methylamines process can increase the capacity by about 30 - 50 % and reduce the energy consumption by about 40 - 50 X in existing installations and can require about 30 - 40 % less capital investment in new plants [55]. 

As of the early 1990s, practically all the commercial methylamine processes are based on the technology of methanol alkylation of ammonia. 

A typical methylamines process is divided into three sections synthesis, refining, and waste recovery (see Fig. 28.23). 

To make methylamine we start with Acetamide. The general, unbalanced reaction process is thus ... 

Purification of the Methylamine HCI is in order now, so transfer all of the crude product to a 500mL flask and add either 250mL of absolute Ethanol (see end of FAQ for preparing this) or, ideally, n-Butyl Alcohol (see Footnote 4). Heat at reflux with a Calcium Chloride guard tube for 30 minutes. Allow the undissolved solids to settle (Ammonium Chloride) then decant the clear solution and cool quickly to precipitate out Methylamine HCI. Filter rapidly on the vacuum Buchner funnel and transfer crystals to a dessicator (see Footnote 3). Repeat the reflux-settle-cool-filter process four... 

A modification of the direct process has recentiy been reported usiag a ckculating reactor of the Buss Loop design (11). In addition to employing lower temperatures, this process is claimed to have lower steam and electricity utihty requirements than a more traditional reactor (12) for the direct carbonylation, although cooling water requirements are higher. The reaction can also be performed ia the presence of an amidine catalyst (13). Related processes have been reported that utilize a mixture of methylamines as the feed, but require transition-metal catalysts (14). 

MMHa.nd UDMH. MonomethyUiydrazine and yyz -dimethylhydrazine are manufactured by Olin Corp. using the same Raschig process and equipment employed for anhydrous hydrazine. Chloramine, prepared as described above, reacts with methylamine or dimethylamine instead of with... 

Du Pont has lepoited an alternative catalytic process for the production of MIC starting with methylamine [74-89-5J (32). 

In this thiamine pyrophosphate-mediated process, ben2aldehyde (29), added to fermenting yeast, reacts with acetaldehyde (qv) (30), generated from glucose by the biocatalyst, to yield (R)-l-phen5l-l-hydroxy-2-propanone (31). The en2ymatically induced chiral center of (31) helps in the asymmetric reductive (chemical) condensation with methylamine to yield (lR,23)-ephedrine [299-42-3] (32). Substituted ben2aldehyde derivatives react in the same manner (80). 

Naphthol is mainly used in the manufacture of the insecticide carbaryl (59), l-naphthyl A/-methyicarbamate/ iJ-2j5 - (Sevin) (22), which is produced by the reaction of 1-naphthol with methyl isocyanate. Methyl isocyanate is usually prepared by treating methylamine with phosgene. Methyl isocyanate is a very toxic Hquid, boiling at 38°C, and should not be stored for long periods of time (Bhopal accident, India). India has developed a process for the preparation of aryl esters of A/-alkyl carbamic acids. Thus l-naphthyl methylcarbamate is prepared by refluxing 1-naphthol with ethyl methylcarbamate and POCl in toluene (60). In 1992, carbaryl production totaled > 11.4 x 10 t(35). Rhc ne-Poulenc, at its Institute, W. Va., facihty is the only carbaryl producer in United States. 

Mannich has prepared arecaidine aldehyde (IV) by allowing a mixture of formaldehyde, acetaldehyde and methylamine hydrochloride to stand at 70° and pK 3. Some dialdehyde, MeN(CH2. CHa. CHO)2, is formed and this by loss of water produces arecaidine aldehyde. The latter is, converted into arecoline by the VVohl and Johnson process described above. 

Merck and Maeder have patented the manufacture of arecaidine by loss of water from l-methyl-4-hydroxypiperidine-3-carboxylic acid. A method of producing the latter has been describd by Mannich and Veit and has been developed by Ugriumov for the production of arecaidine and arecoline. With the same objective, Dankova, Sidorova and Preobrachenski use what is substantially McElvain s process,but start by converting ethylene oxide, via the chlorohydrin and the cyanohydrin, into -chloropropionic acid. The ethyl ester of this with methylamine in benzene at 140° furnishes methylbis(2-carbethoxyethyl) amine (I) which on refluxing with sodium or sodium Moamyloxide in xylene yields l-methyl-3-carbethoxy-4-piperidone (II). The latter is reduced by sodium amalgam in dilute hydrochloric acid at 0° to l-methyl-3-carbethoxy-4-hydroxypiperidine (III) which on dehydration, and hydrolysis, yields arecaidine (IV R = H), convertible by methylation into arecoline (IV R = CH3). 

Methylamine Hydrochloride.- -This reaction, which yields the ])riiviary amine, is appheahie, not only to thealijihatic, hill, dsci Ic) tlieaiomatic. innclcs. The lonnation ofanthianilicacid from ]jhth diinidc is a process of technical importance. 13y the... 

Methylchloramine can be prepared by adding an aqueous solution of sodium hypochlorite to an aqueous solution of methylamine in accordance with the process described by W.S. Metcalf, J. Chem. Soc. 1942,148. 

Table II must be used with care in anomalous cases in which the transition probability for ionization of the molecule is very low in some energy ranges (e.g., acetylene, benzene, methylamine). In such cases higher RE s, not included in the table and normally of small importance, may be responsible for the charge exchange processes although with small cross-sections (cf. 9, 13).

Ammonia has always been the starting material for the synthesis of aliphatic amines. Thus, processes have been developed for the condensation of NH3 with alkyl halides (Hoffman reaction) or with alcohols in the presence of various catalysts. The latter reachon, first discovered by Sabatier in 1909 [8, 9] is nowadays the main method of industrial production of light amines (e.g. methylamines 600 000 t/yr) [5]. 

The domino approach is also used by Nature for the synthesis of several alkaloids, the most prominent example being the biosynthesis of tropinone (0-16). In this case, a biomimetic synthesis was developed before the biosynthesis had been disclosed. Shortly after the publication of a more than 20-step synthesis of tropinone by Willstatter [14], Robinson [15] described a domino process (which was later improved by Schopf [16]) using succinaldehyde (0-13), methylamine (0-14) and acetonedicarboxylic acid (0-15) to give tropinone (0-16) in excellent yield without isolating any intermediates (Scheme 0.5). 

Another beautiful example of an early domino process is the formation of daphnilactone A (0-19), as described by Heathcock and coworkers [17]. In this process the precursor 0-17 containing two hydroxymethyl groups is oxidized to give the corresponding dialdehyde, which is condensed with methylamine leading to a 2-azabutadiene. There follow a cycloaddition and an ene reaction to give the hexacycle 0-18, which is transformed into daphnilactone A (0-19) (Scheme 0.6). 

A straightforward application of an Ugi reaction in natural product synthesis has been elucidated by Bauer and Armstrong [53]. These authors prepared the intermediate 9-68 in the synthesis of the complex protein phosphatase inhibitor motuporin (9-69), by using an U-4CR process starting from the acid 9-64, the aldehyde 9-65, methylamine, and the isocyanide 9-66 via 9-67. 

The dimeric 2,3-dihydro-l,2,4-oxadiazole palladium(n) complex 182 (Equation 27) reacts with aqueous methylamine to liberate the ligand 183 <2003JCD2544>. A similar process has also been applied to platinum(lv)-bound complexes 184, using pyridine to liberate the 2,3-dihydro-l,2,4-oxadiazole <2000JA3106>. Reduction of the platinum(iv) complexes 184 (Equation 28) gives the corresponding platinum(n) complexes 185 <2001IC264>. 

The 2,3-dihydro-l,2,4-oxadiazoles are easily displaced from the complexes 364 with aqueous methylamine (MX = PdCl2) and with pyridine (MX = PtCl4), and less easily with PPh3 (M = PtCl2) an example of this process is shown in Equation (74) <2001IC264>. 

Alceru A process for making cellulosic filaments and staple fibres. The cellulose is first dissolved in an aqueous solution of N-methylamine-N-oxide. Developed by Zimmer (Frankfurt) and TITK (Rudolstadt) from 1987. A pilot plant was expected to be built by April... 

Leonard A process for making mixed methylamines by reacting ammonia with methanol over a silica-alumina catalyst at elevated temperature and pressure. Developed and licensed by the Leonard Process Company. In 1993, the installed worldwide capacity of this process was 270,000 tonnes/y. 

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