Methylamine Subject

These pyridazines are subject to direct deactivation of the leaving group. It would appear from the conditions used in its reactions with ammonia (115°) and methylamine (50°) that 4-chloro-2-ethylthiopyrimidine (225) is somewhat deactivated (indirect). In various aminations of pyrimidines, the effect of an alkylthio group seems to be very mildly deactivating, like that of methyl groups. However, these surmises from the conditions used are not as reliable as the direct qualitative comparison described above and the kinetic data. 

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... 

AIC was heated with methylamine under pressure at 70-80°C for several hours, and the reaction mixture was subjected to HPLC/MS and MS/MS analysis. This analysis showed that the expected A-mcthylamidc, (XXVm), had been produced, along with a number of other products (not identified). 

The resulting dynamic aminonitrile systems were first subjected to lipase mediated resolution processes at room temperature. A-Methy] acetamide was observed as a major product from the lipase amidation resolution. In this case, free methylamine A was generated during the dynamic transimination process and transformed by the lipase. To avoid this by-reaction, the enzymatic reaction was performed at 0 °C, and the formation of this amide was thus detected at less than 5% conversion. To circumvent potential coordination, and inhibition of the enzyme by free Zn(II) in solution [54], solid-state zinc bromide was employed as a heterogeneous catalyst for the double dynamic system at 0 °C. The lipase-catalyzed amidation resolution could thus be used successfully to evaluate /V-substituted a-aminonitrile substrates from double dynamic systems in one-pot reactions as shown in Fig. 7d. Proposedly, the heterogeneous catalyst interfered considerably less or not at all in the chemo-enzymatic reaction because the two processes are separated from each other. Moreover, the rate of the by-reaction was reduced due to strong chelation between the amine and zinc bromide in the heterogeneous system. 

Dideoxynucleosides show potent anti-retroviral activity against HIV-specific reverse transcriptase80-83. In particular, 2, 3 -dideoxy-3 -C-cyano-2 -substituted thymidine derivatives (33 A and 33 B) with a free 5 -hydroxy function (R1 = H) are potential inhibitors of the HIV-reverse transcriptase-promoted c-DNA synthesis. As these compounds have yet to be prepared by another method, the 3 -ene-nitrile 3284 was subjected to conjugate addition reactions with ammonia, primary amines, secondary amines and carbon nucleophiles. Most of these nucleophilic amine addition reactions give either the trans-isomer 33 A as the sole product (e.g., reaction with pyrrolidine, piperidine, morpholine), or as the major product along with the c/s-isomer (e.g., reaction with methylamine, benzylamine), except for the reaction with ammonia where the cts-isomer 33B is formed as the major product84. 

Before leaving the subject of 3,5-cyclosteroids, comment must be made about unusual situations where inverted 3 a-substituted products are formed from cholesteryl tosyiate and similar steroids. Several authors have recorded the occurrence of Sjt2 substitutions, with Walden inversion at C 3>, by powerful nucleophiles. These reactions occur particularly in solvents of low dielectric constant, where ionisation processes become relatively unfavourable. Ammonia, methylamine, and benzyl-amine are sufficiently reactive as nucleophiles to give moderate yields of the corresponding AS-3a-amines [33,36], and the more powerfully nucleophilic dimethylamine is reported to give virtually complete conversion into the ga-dimethyl-amino-A -derivative [36]. Other reactive nucleophiles which... 

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). ... 

The primary photochemistry of methylamine, as established from classical bulk experiments, has been reviewed by Michael and Noyes [262], who until recently provided the most definitive work on this subject. These studies suggest that Eq. 15 is the dominant (ca. 75%) dissociation pathway following excitation within the first continuum, but also identified products arising from C—H bond fission (Eq. 16), C—N bond cleavage (Eq. 17), and the molecular elimination channel (Eq. 18) ... 

When the 1,3-indanedione 1-phenylhydrazone (89) was subjected to a double Mannich reaction using benzylamine or methylamine and formaldehyde in the presence of a small amount of acetic acid, it afforded (60-65% yield) the indano-1,2,4-triazepines (90) (Scheme 14) <90ZN(B)80>. The NMR spectra indicate that (90) existed in solution as mixtures of keto and enol tautomers. Similarly,... 

A heterogeneous mixture of solid potassium cyanide (0.651 g, 10 mmol), solid methylamine hydrochloride (0.753 g, 11 mmol) and neutral alumina (for column chromatography, 1.5 g) in acetonitrile (4 mL) is placed in a Pyrex test tube (25 mm diameter, 150 mm) with a Teflon -lined screw cap. The mixture is subjected to preliminary sonication at 50°C for 10 min in a thermostated Branson cleaner (100 W, 45 kHz). Benzaldehyde (0.531 g, 5 mmol) was then added and sonication was continued for 5 h. Solid materials were filtered off through a Celite pad and the filtrate was concentrated on a rotary evaporator. The crude product was purified by short column chromatography to give a-methylamino-phenyl-acetonitrile. IR (neat) 3380, 3320, 2225 cm-1. iR NMR (CDCI3, TMS) 6 7.45 (m, 5H), 4.80 (s, IH), 2.65 (s, 3H), 1.65 (br. s, IH) ppm. 

On the 102 surface, the nitrogen atom of methylamine was placed at 2.10 A from the surface calcium atom and the assembly was subjected to energy minimization. The surface exhibited stabilization, and the adsorption energy was near that of methanoic acid adsorption. As shown in Figure 3.17c, methylamine adsorbed on the valley region of the surface with its C-N axis between the... 

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