Hydrochloric acid with methylamine

At the end of this time, allow to cool then add enough 25% Sodium Hydroxide solution to to get the pH above 11. Heat on a water bath or with gentle electric heat to drive the Methylamine off as a gas into the same beaker of Hydrochloric acid used as a trap during the reaction. 

Hexamine, more formally known as Hexamethylenetetramine, is easily and conveniently produced from Formaldehyde and Ammonia solutions. Formaldehyde may be easily produced by depolym-erizing, with heat, Paraformaldehyde (the only ingredient in OTC MildewCide). Hexamine is then reacted with Hydrochloric Acid and heated to yield Methylamine HCI in near quantitative yield. 

For example, the action of a-thiocyanatoacetone on ammonia in ether solution gives 4-methyl-2-aminothiazole but in very low yield (137). Methylamine in ether at 0°C gives in a first step S-acetonyl N-methylisothiourea (196) in 80% yield (Scheme 102) (137). The cycliza-tion of this intermediate occurs either after a prolonged rest at room temperature, either by fusion or by heating with dilute hydrochloric acid to afford the 4-methyl-2-methylaminothiazole (197). 

When trigonelline is heated in closed tubes with baryta water at 120°, it gives rise to methylamine, whilst similar treatment with hydrochloric acid at 260° furnishes methyl chloride and nicotinic acid (pyridine-3-carboxylic acid), indicating that it is the methylbetaine of nicotinic acid. 

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). 

A mixture of 114.5 g of 5-(3-chloropropylidene)dlbenzo[a i] cyclohepta[1,4] diene, 75 ml of benzene, and about 400 ml of methylamine is heated in an autoclave at 120°Cfor six hours. The excess methylamine is distilled from the reaction mixture under vacuum and the residue is stirred with 300 ml of water. Acidification of the mixture with hydrochloric acid causes the separation of the hydrochloride of 5-(3-methylaminopropylidene)dlbenzo[a,dlcyclo-hepta[ 1,4] diene. The product is collected by filtration and is purified by recrystallizatlon from a mixture of absolute ethanol and ethyl acetate. MP 210°C to 212 C. 

Methylamine hydrochloride method. Place 100 g. of 24 per cent, methyl-amine solution (6) in a tared 500 ml. flask and add concentrated hydrochloric acid (about 78 ml.) until the solution is acid to methyl red. Add water to bring the total weight to 250 g., then introduce l50 g. of m%a, and boil the solution gently under reflux for two and three-quarter hours, and then vigorously for 15 minutes. Cool the solution to room tempara-ture, dissolve 55 g. of 95 per cent, sodium nitrite in it, and cool to 0°. Prepare a mixture of 300 g. of crushed ice and 50 g. of concentrated sulphiuic acid in a 1500 ml. beaker surrounded by a bath of ice and salt, and add the cold methylurea - nitrite solution slowly and with mechanical stirring and at such a rate (about 1 hour) that the temperature does not rise above 0°. It is recommended that the stem of the funnel containing the methylurea - nitrite solution dip below the siu ace of the acid solution. The nitrosomethylurea rises to the siuface as a crystalline foamy precipitate. Filter at once at the pump, and drain well. Stir the crystals into a paste with about 50 ml. of cold water, suck as dry as possible, and dry in a vacuum desiccator to constant weight. The yield is 55 g. (5). 

However, with liquid ammonia or anhydrous methylamine 1,2,4-oxadiazines (88) are formed. 5-(Chloromethyl)-l,2,4-oxadiazoles (e.g., (86) react with urotropin to form salts, which are hydrolyzed with hydrochloric acid to 5-(aminomethyl) compounds (the Delepine reaction). Alternatively, 5-(aminomethyl)-l,2,4-oxadiazoles have been prepared by condensation of amidoximes with a-amino-acids <72JHC435>. 

Some of the earliest attempts to prepare dehydrocorrin derivatives used a tetrapyrrole compound already containing a direct linkage between the two central rings. When its palladium(Il) derivative was treated with formaldehyde and hydrochloric acid it underwent cyclization but with the insertion of an oxygen atom rather than the desired carbon bridge (equation 51).261 Subsequent treatment of the same starting material with ammonia, methylamine or sodium sulfide gave rise to related macrocyclic products. 

Tris(hydroxymethyl)methylamine (TRIS), sodium chloride, sodium citrate, ethylenediamine tetraacetic acid disodium salt (EDTA), lithium chloride, Tween 20, streptavidin 10 nm colloidal gold labelled, hydrochloric acid (37%), nitric acid, streptavidin-coated paramagnetic beads (MB) with a diameter of 2.8 pm, Dynabeads M-280 Streptavidin (Dynal Biotech, Oslo, Norway) biotinylated probe oligonucleotides which sequences are shown in Table 53.1. 

Crude 5-nitroisophthalic acid, monomethyl ester (46.3 g, 0.21 mole) was dissolved in 35% aqueous methylamine solution (500 ml). On standing, the orange solution became blood red. The reaction mixture was evaporated overnight on the steam bath, the cool residue was treated with 50 ml of water and the solution was acidified with hydrochloric acid. A yellow precipitate of crude N-methyl-5-nitroisophthalamic acid was separated and dried (yield 41.5 g). This acid was redissolved in dilute ammonia solution and the resulting solution (pH 5.2) was treated with charcoal. Acidification of the treated solution yield a pale yellow product of neutral equivalent 213. A small portion (10 g) was recrystaliized from 1 1 water-ethanol (300 ml) to yield orange N-methyl-5-nitroisophthalamic acid. M.p. 251°-252.5°C. 

Hydroxypropyl)anthracene was prepared by reduction of 3-(9-anthryl) propionic acid with LiAIH4. By action of thionylchloride and then methylamine the 9-(3-hydroxypropyl)anthracene was converted to 9-(3-methylaminopropyl) anthracene. By addition of ethylene to 9-(3-methylaminopropyl)anthracene (at 150°C, a pressure of ethylene 50 atm, 24 hours) was obtained 3-(9,10-dihydro-9,10-ethanoanthracene-9-yl)-N-methylpropylamine. Hydrochloride 3-(9,10-dihydro-9,10-ethanoanthracene-9-yl)-N-methyl propylamine may be prepared by action hydrochloric acid. 

Diethoxyethyl)methylamine reacted with potassium thiocyanate in the presence of hydrochloric acid and give the thiamazole, yellow crystallic precipitate, melting point 144°-147°C. 

The methylamine hydrochloride used in checking was prepared by neutralizing a commercial 33 per cent aqueous solution of methylamine with concentrated hydrochloric acid, evaporating to dryness, and crystallizing once from 95 per cent ethyl alcohol. 

The first route was rather straight forward introducing first the nitrogen containing side chain by reacting the epoxide with methylamine in methanol at 120 °C under pressure to the amino-alcohol 215 and N-alkylation of this intermediate with 1-bromoheptane in ethanol to the tertiary amine 216. This same product was prepared directly by reaction of the epoxide with N-methylheptylamine in ethanol with a catalytic amount of hydrochloric acid at 120 °C under pressure. O-alkylation was performed according to the method used by J. Fried69) that is reaction of 216 with tert. butyl-oj-iodohexanoate (NaH in DMSO). Compound 217 was charac-... 

The thermal degradation of arecaidine methyl betaine (167) and the subsequent work-up with hydrochloric acid gave a mixture of 5-di-methylamino-l,3-pentadiene (159), m-2-pentenal (170), and di-methylamine. The 1,2-diene (168) and the enamine (169) are assumed as the unisolated intermediates.131... 

Tlie two major chemical reactions tliat were occurring in Uie Bhopal plant produced carbaiyl using metliyl isocyanate (MIC) as an intermediate. Tlie first of the consecutive reactions combined methylamine and phosgene to produce MIC tmd hydrochloric acid. Then Uie MIC reacts wiUi a-naphUiol to form Uie final product, carbaryl. There is another possible route to produce carbaiyl Uiat does not make use of the MIC intermediate. Instead, phosgene is first reacted with a-naphUiol to form a-naphthol chloroformate - Uie intermediate for Uie reaction and hydrochloric acid. Tlien a-naphUiol clUoroforniate reacts wiUi nieUiylamine to form carbaryl and hydrochloric acid. Both reaction schemes (depicted below) have Uie same overall stoichiometric equation. 

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