Aqueous methylamine

Dimethylaminomethylindole (gramine). Cool 42 5 ml. of aqueous methylamine solution (5 2N ca. 25 per cent, w/v) contained in an 100 ml. flask in an ice bath, add 30 g. of cold acetic acid, followed by 17 -2 g. of cold, 37 per cent, aqueous formaldehyde solution. Pour the solution on to 23 -4 g. of indole use 10 ml. of water to rinse out the flask. Allow the mixture to warm up to room temperature, with occasional shaking as the indole dissolves. Keep the solution at 30-40° overnight and then pour it, with vigorous stirring, into a solution of 40 g. of potassium hydroxide in 300 ml. of water crystals separate. Cool in an ice bath for 2 hours, collect the crystalline solid by suction flltration, wash with three 50 ml. portions of cold water, and dry to constant weight at 50°. The yield of gramine is 34 g. this is quite suitable for conversion into 3-indoleacetic acid. The pure compound may be obtained by recrystaUisation from acetone-hexane m.p. 133-134°. 

Now, contrary to popular opinions, this method need not be conducted in a sealed pipe bomb. Secondary amination by substitution is as much a reaction of opportunity as it is of brute force and heat. In fact, heating can tend to cause the reformation of safrole and isosafrole. So the simplest way to do this would be to use 500mL of ammonium hydroxide or alcoholic ammonia or, for those wishing to make MDMA or meth, 40% aqueous methylamine or alcoholic methylamine (to tell you the truth, methylamine is preferable in this method because it is more reactive that ammonia so yield will increase). This 500mL is placed in a flask and into it is poured a solution of 35g bromosafrole (30g phenylisopropyl-bromide) mixed with 50mL methanol. The flask is stoppered and stirred at room temperature for anywhere from 3 to 7 days. The chemist could also reflux the same mixture for 6-12 hours or she could throw the whole mix into a sealed pipe bomb (see How to Make section) and cook it for 5 hours in a 120-130°C oil bath. 

Laurylmethylamine has been prepared by the reaction of lauryl alcohol with methylamine under pressure in the presence of catalysts at high temperature, by heating lauryl chloride with methylamine in alcoholic or aqueous medium under pressure, and by the reaction of lauryl halides with aqueous methylamine. Cetylmethylamine has been prepared by the catalytic debenzyla-tion of benzylcetylmethylamine. ... 

Technical aqueous methylamine solution (28-33 Per cent) may be used. The amine content should be determined by titration with standard acid. 

Pyrolysis of the methylamine salt (produced by neutralising mucic acid with aqueous methylamine) in the presence of glycerol yields IV-methylpyrrole ... 

In a more recent study, Westman and Lundin have described solid-phase syntheses of aminopropenones and aminopropenoates en route to heterocycles [32], Two different three-step methods for the preparation of these heterocycles were developed. The first method involved the formation of the respective ester from N-pro-tected glycine derivatives and Merrifield resin (Scheme 7.12 a), while the second method involved the use of aqueous methylamine solution for functionalization of the solid support (Scheme 7.12 b). The desired heterocycles were obtained by treatment of the generated polymer-bound benzylamine with the requisite acetophenones under similar conditions to those shown in Scheme 7.12 a, utilizing 5 equivalents of N,N-dimethylformamide diethyl acetal (DMFDEA) as reagent. The final... 

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>. 

The checkers used 40% aqueous methylamine supplied by Matheson, Coleman and Bell. 

Alternatively, dissolve 220 g 4-benzyloxy-3-indoleacetic acid (or equimolar amount other indoleacetic acid) in 2 L absolute methanol and reflux six hours in the presence of 20 g Dowex 50X8 sulfonic acid resin. Filter (decolor with carbon if desired) and concentrate below 35° until precipitation starts then cool to precipitate and filter to get 200 g of the methyl ester. Add 200 g of the ester to 600 ml 40% aqueous methylamine over twelve hours with vigorous stirring. Filter, wash precipitate with water and dry to get 187 g of the N-methyl-acetamide (reflux two hours in 500 ml benzene to remove unreacted ester). 24 g of the acetamide in 300 ml tetrahydrofuran is added dropwise to 10 g lithium aluminum hydride in 300 ml tetrahydrofuran reflux ten hours, cool to 15° and add dropwise with stirring 50 ml ethyl acetate. Reflux two hours and proceed as above to get 15 g (II) or analog. 

Aqueous methylamine (64 ml, 33.2 mmol) was added to 1,1 -bis(diphenylphospino) 2,2 -bis(a-acetoxyethyl)ferrocene (403 mg, 0.55 mmol) in isopropanol (5 ml) and the reaction mixture was stirred in a closed pressure ampoule at 90°C for 66 hours. After evaporation in vacuo, the residue was dissolved in ethyl acetate/heptane 1 1 and extracted with 10% aqueous citric acid. The aqueous phase was washed with ethyl acetate/heptane 1 1, basified with 2N NaOH basic and... 

Prepd by treating the 2-nitrimino compd wi thmitrous acid (Ref 2). Treatment with aqueous methylamine at 5-7° displaces the V-WO with an —H (Ref 4)... 

A total of 320 g. (1.68 moles) of />-toluenesulfonyl chloride (Note 1) is divided into three portions of 190, 90, and 40 g. and a solution of alkali is prepared by dissolving 70 g. of sodium hydroxide in 70 ml. of water with cooling. The 190-g. portion of the sulfonyl chloride is added with swirling during about 5 minutes to 210 ml. (2.1 moles) of 33% aqueous methylamine (or 174 ml. of the 40% solution) contained in a 1-1. round-bottomed flask. The mixture is allowed to heat up to 80-90° in order to maintain the sulfonylmethylamide (m.p. 78°) in a molten condition (Note 2). After all this portion of the sulfonyl chloride has been added, the mixture is shaken vigorously. Boiling is prevented by mild cooling with water in order to avoid an excessive loss of methyl-amine. 

Dinitrd iethylanilme is produced by the reaction of chlorodinitrobenzene with methylamine in the presence of sodium hydroxide. A solution is prepared consisting of 300 1. of water, 1140 1. of 35% aqueous sodium hydroxide solution and 1225 kg of 25% aqueous methylamine solution. This solution is added over a period of 12 hr to a vigorously stirred suspension of 2000 kg of chlorodinitrobenzene in 1350 1. of water heated to 95-100°C. 

Ethyl-M-methylcarbamate has been prepared by adding aqueous methylamine to ethyl chloroformate 1 and from methyl car-bamyl chloride and ethyl alcohol.2... 

Methylamine hydrochloride can be used in place of the commercial aqueous methylamine solution by a slight modification of the above procedure. The carbon disulfide and a solution of 122 g. (1.8 moles) of methylamine hydrochloride in 200 cc. of water are mixed together in the flask, and a cold solution of 144 g- (3-6 moles) of sodium hydroxide in 320 cc. of water is added, with stirring, over a period of thirty minutes. Two equivalents of sodium hydroxide must be used in this case. The remainder of the procedure is the same as with the free base. 

A. N-Nilroso-fi-methylaminoisobutyl methyl ketone. In a 2-1. three-necked flask, fitted with a mechanical stirrer, a thermometer, and a dropping funnel, is placed 250 ml. (2.1 moles) of 30% aqueous methylamine (Note 1). The flask is surrounded by an ice bath, and the stirrer is started. When the temperature of the solution has dropped to 5°, 196 g. (2 moles) of mesityl oxide is added through the dropping funnel at such a rate that the temperature remains below 20° (Notes 2 and 3). After the mesityl oxide has been added, the mixture is allowed to stand without cooling for 30 minutes. 

In cases where metals or metal ions can contaminate the products, reaction vessels fabricated from inert polymeric materials restrict that possibility. A significant example involved the reaction of maltol with aqueous methylamine to give l,2-dimethyl-3-hydroxypyrid-4-one. The product is a metal chelator employed for the oral treatment of iron overload. Consequently, it is an excellent metal scavenger but must be produced under stringent conditions that preclude metal complexation. Literature conditions involved heating maltol in aqueous methylamine at reflux for 6 h, the product was obtained in 50% yield, but required decolourisation with charcoal135. With the CMR, the optimal reaction time was 1.3 min, and the effluent was immediately diluted with acetone and the near colourless product crystallised from this solvent in 65% yield (Scheme 9.18). A microwave-based batch-wise preparation of 3-hydroxy-2-methylpyrid-4-one from maltol and aqueous ammonia was also developed. 

CH3NH2 HC1 (aq.). Muller1 6 measured the heat of reaction of aqueous methylamine with aqueous HC1 to be 13.0. 

CH3NH3+ (aq.). The value for aqueous methylaminium ion is obtained from aqueous methylamine hydrochloride. 

The benzo[ 1,2,5]thiadiazepine 108 upon reaction with an equimolar amount of aqueous methylamine and Et3N furnishes a mixture of 109 and 110 in 15% and 19% yields, respectively, whereas an excess of methylamine afforded exclusively 111 (Scheme 24) <1996FES425>. 

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