Methylamine generator

Benkeser and Tincher 128>, on the other hand, reduced acetylenes preferentially to trans olefins using solvated electrons generated at a platinum cathode by electrolytic reduction of lithium chloride in methylamine [lithium metal is formed from lithium ion at the cathode in this electrolysis its dissolution in methylamine generates the solvated electron and regenerates lithium... 

The methylamine generator consists of a i-l. flask fitted with a dropping funnel and outlet tube, which in turn is connected to a 25-cm. drying tower containing soda-lime, followed by a i-l. safety trap (Note 1). In the flask is placed 200 g. of technical sodium hydroxide flakes, and 263 g. of a 33-35 per cent solution of methylamine in water (Note 2) is dropped in slowly at such a rate that an even current of gas is evolved. When the addition has been completed and the gas bubbles very slowly into the... 

FIA combined with CL has been also used for detection of carbofuran and prome-carb (Figure 5.3) (Perez-Ruiz et al., 2002), atrazine, and other triazines (Beale et al., 2009) by making use of the property of the pesticides to be converted into methylamine upon exposure to UV radiation. The methylamine generated is made to react with tris-ruthenium, allowing the CL detection of triazines. 

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). 

Fig. 3. Synthesis of fluoxetine (31). 3-ChIoro-I-phenyl-I-propanol reacts with sodium iodide to afford the corresponding iodo derivative, followed by reaction with methylamine, to form 3-(methyl amin o)-1-phenyl-1-propan 0I. To the alkoxide of this product, generated using sodium hydride, 4-fluorobenzotrifluoride is added to yield after work-up the free base of the racemic fluoxetine (31), thence transformed to the hydrochloride (51)...

Iminium ions bearing an electron-withdrawing group bonded to the sp carbon of the iminium function are very reactive dienophiles. Thus, iminium ions 26 generated from phenylglyoxal (Scheme 6.15, R = Ph) or pyruvic aldehyde (R = Me) with methylamine hydrochloride, react with cyclopenta-diene in water at room temperature with good diastereoselectivity [25] (Scheme 6.15). If glyoxylic acid is used, the formation of iminium salt requires the free amine rather than the amine hydrochloride. 

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 C-H insertion a to nitrogen can be extended to acyclic systems. The reaction with jY-benzyl-iV-methylamine is an excellent example of the interplay between steric and electronic effects. The benzylic position would be electronically the most activated, but due to the steric crowding, the C-H insertion occurred exclusively at the iV-methyl site (Equation (27)).86 This is a general method for generating a-aryl-/5-amino acid derivatives. The N,N-dimethylamino group undergoes a very favorable C-H insertion by the donor/acceptor-substituted carbenoids. Indeed, the reaction is so favorable that double C-H insertion was readily achieved to form the elaborated -symmetric amine 10 (Equation (28)).87... 

Keefer LK, Anjo T, Wade D, et al. Concurrent generation of methylamine and nitrite during denitrosation of N-nitrosodimethylamine by rat liver microsomes. Cancer Res 1987 47(2) 447-452. 

Methylamine (19) is useful as a nucleophile for generating derivatives from activated acids. 

Some studies have focused on the generation of the corresponding radical cations of methylamine, dimethylamine and TV-methylpiperidine2,3 by /-irradiation at low temperature. The radical cation of t-BuNH2 can be formed (k = 3.4 x 106 M-1 s 1) by oxidation with DMSO-C14. 

Dimethylolnitramine (252) readily participates in Mannich condensation reactions treatment of a aqueous solution of (252) with methylamine, ethylenediamine and Knudsen s base (254) (generated from fresh solutions of ammonia and formaldehyde) yields (253), (255) and (239) (DPT) respectively. The cyclic ether (258) is formed from the careful dehydration of dimethylolnitramine (252) under vacuum. ... 

Structures have been determined for [Fe(gmi)3](BF4)2 (gmi = MeN=CHCF[=NMe), the iron(II) tris-diazabutadiene-cage complex of (79) generated from cyclohexanedione rather than from biacetyl, and [Fe(apmi)3][Fe(CN)5(N0)] 4F[20, where apmi is the Schiff base from 2-acetylpyridine and methylamine. Rate constants for mer fac isomerization of [Fe(apmi)3] " were estimated indirectly from base hydrolysis kinetics, studied for this and other Schiff base complexes in methanol-water mixtures. The attenuation by the —CH2— spacer of substituent effects on rate constants for base hydrolysis of complexes [Fe(sb)3] has been assessed for pairs of Schiff base complexes derived from substituted benzylamines and their aniline analogues. It is generally believed that iron(II) Schiff base complexes are formed by a template mechanism on the Fe " ", but isolation of a precursor in which two molecules of Schiff base and one molecule of 2-acetylpyridine are coordinated to Fe + suggests that Schiff base formation in the presence of this ion probably occurs by attack of the amine at coordinated, and thereby activated, ketone rather than by a true template reaction. ... 

TMA, its N-oxide and related aliphatic amines like methylamine and dimethylamine in urine may be quantified using head-space gas chromatography [28] or direct injection of the head-space gas into the gas sample injection port of a mass spectrometer [27]. These methods take advantage of the volatility of the amines and evaluate the amine-rich head-space gas generated above the sample by direct injection. The... 

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