Methylamine degradation

It was necessary to allow several hours for the formation of the N-chloroamide before heating to degradation temperature. With this modification it was possible to prepare methylamine...consistently in 78% yield."... 

Paraquat is used to control aquatic weeds. It also passes into aquatic environments through rain, where it is rapidly accumulated by aquatic organisms, especially fish (Gabryelak and Klekot 1985). Paraquat applied to control aquatic weeds is accumulated by aquatic macrophytes and algae, and it is adsorbed to sediments and suspended materials. Initial applications of 1 to 5 mg/L in the water column are usually not detectable under field conditions after 8 to 27 days (Summers 1980). The half-time persistence of paraquat in water column at normal doses for weed control (i.e., 0.5 to 1.0 mg/L) was 36 h less than 0.01 mg/L was detectable in 2 weeks (Calderbank 1975). In solution, paraquat was subject to photodecomposition and microbial metabolism, degrading to methylamine... 

Thebaine, codeine and morphine from poppy straw (Papaver somniferum) were extracted with carbon dioxide and various polar modifiers at 20 MPa and 40.5 °C. Kinetic extraction curves for morphine showed that 50% methanol in carbon dioxide was necessary in order to achieve quantitative yields in less than 20 min. A mixture of 25% methanol, 0.22% methylamine and 0.34% water had the same effect as 50% methanol in the catbon dioxide. However, it was also reported that, in spite of its strong extraction power, the methylamine-water mixture had a major drawback in that morphine in the presence of the amine degraded in the presence of light. Hence, carbon dioxide-methanol-water mixtures were investigated increasing the water content in the extraction fluid dramatically enhanced the extraction rate for thebaine [29]. 

Polyurethanes (PU) The odor of many polyurethanes is caused by fishy smelling low molecular weight amines, mostly methylamines like trimethylamine, degradation products of the amine catalysts used during production. In some cases after evaporation of the fishy smelling amines, other odor qualities remain. One noticeable odor of PU samples was earthy, nutty, which can often be attributed to substituted pyrazines, formed by condensation of two a-aminoketones, subsequent oxidation or alkylation by aldehydes. One example is 2-ethyl-3,5-dimethylpyrazine (Mayer and Breuer, 2006). 

Ruveda and co-workers have shown that the /5-hydroxyleucine, of which the aryl ether function in frangulanine is constructed, is present in the erythro-L-form (21). Dihydrofrangulanine was reduced with lithium in methylamine to an enol ether of /3-hydroxyleucine which on hydrolysis generated the free amino acid. It was shown that the hydroxyleucine in the hydrolysate is degraded by snake venom l-aminooxidase but not by pig kidney D-aminooxidase. Inasmuch as reo-hydroxyamino acids are attacked by neither enzyme it follows that the /3-hydroxyleucine, of hydrolytic origin, is the L-erythro form. 

Some degradation products react further. For example, all purines are decomposed upon heating in acid media at temperatures above 100°C to glycine, formic acid, carbon dioxide and ammonia. Methylated purines give rise to methylamine instead of ammonia. 

The incorporation of [2-14C]pyruvate and [l-14C]acetate into sugars 17 and 18 was investigated.27 Oxidation of the methyl glycosides of sugar 17 with periodate yielded acetaldehyde from the 1-hydroxyethyl branch. The acetaldehyde (2,4-dinitrophenyl)hydrazone was further oxidized by Kuhn-Roth oxidation to acetic acid, which was degraded by the Schmidt reaction to methylamine and carbon dioxide. Periodate oxidation of the methyl glycosides of sugar 18 produced acetic acid from the C-acetyl branch. The acetic acid was isolated, and purified as 1-acetamidonaphthalene. 

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... 

Limited available data suggest that NDMA would be subject to slow photolysis in natural waters exposed to sunlight (Polo and Chow 1976 Callahan et al. 1979). In unlit waters, it appears that NDMA would be rather persistent, eventually degrading as the result of microbial transformation (Kaplan and Kaplan 1985, Kobayashi and Tchan 1978, Tate and Alexander 1975). There is evidence which suggests that formaldehyde and methylamine may form as biodegradation products of NDMA (Kaplan and Kaplan 1985). Insufficient data are available to predict the rate at which NDMA would degrade in water. NDMA is not expected to chemically react under the conditions found in natural waters (Callahan et al. 1979, O.liver et al. 1979). ... 

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