Dimethy lamine

Carbanions derived from optically active sulfoxides react with esters, affording generally optically active )S-ketoesters ° . Kunieda and coworkers revealed that treatment of (-t-)-(R)-methyl p-tolyl sulfoxide 107 with n-butyllithium or dimethy-lamine afforded the corresponding carbanion, which upon further reaction with ethyl benzoate gave (-l-)-(R)-a-(p-tolylsulfinyl)acetophenone 108. They also found that the reaction between chiral esters of carboxylic acids (R COOR ) and a-lithio aryl methyl sulfoxides gave optically active 3-ketosulfoxides The stereoselectivity was found to be markedly influenced by the size of the R group of the esters and the optical purity reached to 70.3% when R was a t-butyl group. 

Figure 13.13.2 Alternative reduction pathway of trimethylamine oxide to dimethy-lamine and formaldehyde.

The presence of an electron-withdrawing substituent can favor reductions of heterocycles. In this way, the electroreduction of an activated thiopyran affords a dihy-drothiopyran with elimination of dimethy-lamine (Scheme 14) [19]. 

Dacarbazine Dacarbazine, 5-(3,3-dimethyl-l-(riazeno)imidazol-4-carboxamide (30.6.5), is made by diazotation of 5-aminoimidazol-4-carboxamide with nitrous acid, which results in the formation of 5-diazoimidazol-4-carboxamide (30.6.4). Reacting this with dimethy-lamine gives the desired dacarbazine (30.6.5) [146]. 

The IEs on amine basicity are also due to changes in vibrational frequencies, not only computationally but also experimentally. Gas-phase IEs of O.lOkcalmol-1 per CD3 group on basicities of methylamine, dimethy-lamine, and trimethylamine can be reproduced by ab initio force constants for C-H stretching, which increase on TV-protonation.100 Infrared spectra of amines show characteristic bands (called Bohlmann bands ) in the 2700-2800 cm-1 region, lower than the 2900 cm-1 of a typical C-H stretch.169,170 Upon /V-protonation these bands revert to a typical, higher frequency. Therefore the zero-point energy of the C-H increases on... 

The reaction sequence is the same as in part (e) except that dimethy lamine is used as the nucleophile instead of ammonia. 

Miyaki and Fujimoto and co-workers [16,17] have obtained an even finer distribution of fixed charge groups by casting films from multicomponent block copolymers such as poly(isoprene- >-styrene- >-butadiene- >-(4-vinyl benzyl)dime-thylamine- Msoprene). These films show a very regular domain structure with a 200-500 A spacing. After casting the polymer film, the (4-vinyl benzyl) dimethy-lamine blocks were quatemarized with methyl iodide vapor, and the styrene blocks were sulfonated with chlorosulfuric acid. 

The reaction of the tricyclic compound N7P6C19 (28) with dimethy-lamine involves the rupture of one of the central bonds leading to the formation of a bridged-ring imide (29) (330). 

A mixture consisting of 200 ml methyl alcohol, 1680 ml 40% aqueous dimethy-lamine solution, dimethyl ami nc HCl (303 g), and 200 g potassium cyanide (200 g) was added to l,4-dioxaspiro[4.5]decan-8-one (200 g), then stirred 65hours. A white suspension that formed was extracted four times with 800 ml diethyl ether, then concentrated, and the residue dissolved in 500 ml CH2C12. The organic phase was isolated, dried using Na2S04, then concentrated, and 265 g product isolated as a white solid. 

Application Tb produce dimethylformamide (DMF) from dimethy-lamine (DMA) and carbon monoxide (CO). 

The ideal approach for the preparation of conjugated carbonyl compounds having an exo-methylene group would be via a mixed aldol condensation of an enolizable carbonyl substrate with formaldehyde as the electrophilic partner. However, formaldehyde is a very powerful electrophile and tends to react more than once with enols and enolates. This shortcoming can be circumvented by converting the formaldehyde to an iminium ion (Mannich reagent) by reaction with a secondary amine, usually dimethy-lamine, and a catalytic amount of HCl. 

The number of reports on Michael additions of hetero-nucleophiles to enynes bearing an acceptor substituent at the double bond is also rather limited. Bowden and coworkers found that 3-hexen-5-yn-2-one reacts with diethylamine under 1,6-addition to form the 6-amino-substituted dienone (equation 73). Similarly, 1,6-addition products were obtained by Russian groups from reactions of various primary and secondary amines with 2-en-4-ynoates and -nitriles . However, enynoates and nitriles bearing /-hillyI or trimethylsilyl groups at the triple bond were reported to react with methyl- and dimethy-lamine under 1,4-addition, indicating that the regioselectivity of the nucleophihc attack is... 

Jessop and co-workers have pointed out that homogeneous catalysis in supercritical fluids can offer high rates, improved selectivity, and elimination of mass-transfer problems.169 They have used a ruthenium phosphine catalyst to reduce supercritical carbon dioxide to formic acid using hydrogen.170 The reaction might be used to recycle waste carbon dioxide from combustion. It also avoids the use of poisonous carbon monoxide to make formic acid and its derivatives. There is no need for the usual solvent for such a reaction, because the excess carbon dioxide is the solvent. If the reaction is run in the presence of dimethy-lamine, dimethylformamide is obtained with 100% selectivity at 92-94% conversion.171 In this example, the ruthenium phosphine catalyst was supported on silica. Asymmetric catalytic hydrogenation of dehydroaminoacid derivatives (8.16) can be performed in carbon dioxide using ruthenium chiral phosphine catalysts.172... 

Multi-component reaction for the preparation of a variety of compounds in a single step is a powerful tool in combinatorial chemistry and drug discovery. Reaction of cyclohexyliso-nitrile and isobutyraldehyde in methanol in the presence of dimethy lamine hydrochloride as a weak acid catalyst produces A -cyclohexyl-a-dimethylaminoisovaleramide and the corresponding a-hydroxy compound [29] (Scheme 3.17). a-Aminoamidine is obtained as a sole product when dimethylamine is added as a nucleophile. Keung et al. [30] optimized the reaction conditions using various metal catalysts. Scandium (111) triflate was found to be the best catalyst and tolerant to a wide variety of amine and aldehyde units. 

Besides these amines, methylamine, dimethy-lamine, ethylamine, hexylamine, isopentylamine, piperidine, propylamine, pyrrolidine and trypta-mine are also present. 

Buckley and coworkers (1985) have investigated the inhalation toxicity of dimethy-lamine in F-344 rats and B6C3F1 mice. Animals exposed to 175 ppm for 6 h/day, 5 days/week for 12 months showed significant lesions in the nasal passages. Rats developed more extensive olfactory lesions than did mice. The study indicated that olfactory sensory cells were highly sensitive to dimethylamine. Even at a concentration of 10 ppm, the current threshold limit value, the rodents developed minor lesions from exposure. 

DMF hydrolyses into formic acid and dimethy-lamine the water leaving the top of the column (Fig. 16.33) tends to have an unpleasant fishy odour... 

Alkylbenzyldimethylammonium (ABDM) quaternaries are usually prepared from alpha-olefin or fatty alcohol precursors. Manufacturers that start from the fatty alcohol usually prefer to prepare the intermediate alkyldimethylamine directly with dimethy-lamine and catalyst, rather than from the fatty alkyl chloride, although this route is commercially utilized (Figure 14.3). Small volumes of dialkyldimethyl and alkyltrimethyl quaternaries in the Cg-Cio range are also manufactured from these precursors. 

Biological. In both soils and water, chemical and biological mediated reactions can transform thiram to compounds containing the mercaptan group (Alexander, 1981). Odeyemi and Alexander (1977) isolated three strains of Rhizobium sp. that degraded thiram. One of these strains, Rhizobium meliloti, metabolized thiram to yield dimethy-lamine (DMA) and carbon disulfide which formed spontaneously from dimethyldithiocar-bamate (DMDT). The conversion of DMDT to DMA and carbon disulfide occurred via enzymatic and nonenzymatic mechanisms (Odeyemi and Alexander, 1977). 

Volatile aliphatic secondary amines such as diethylamine (bp 55 °C) and dimethy-lamine (bp 7°C) have been used to ring-open azabenzonorbornadienes (Scheme 10.12). To simplify the practical procedure these amines were added as their corresponding hydrogen iodide salts [17b]. 

Dimethy lamine -, Di-butylamine-, Tri-methylamine -, Tri-ethylamine-. Pyridine -, Quinoline hydrochloride Pyridine hydrobromide (CHg)2NCHF2,3HF A cety Ipy ridinium chloride H2NOH, HCl Methiodides Quaternary ammonium salt... 

For conventional amine absorption processes, the amines used (monoethanolamine, diethanolamine, dimethy-lamine, etc.) are unhindered a hindered amine has a bulky alkyl group attached to the amino group as in Figure 5.2.1 (Sartori et al., 1987). The carbamates of such hindered amines are much less stable than the carbamates of the corresponding unhindered amines. For example, the equilibrium constant for the hydrolysis reaction (5.2.18a),... 

Proton transfer from H3O+ to amines is strongly exothermic and reactions are fast. Non-dissociative proton transfer dominates and for some reactions, such as for dimethy-lamine and aniline, this is the sole product channel [40]. Nitriles are similarly sturdy, with acetonitrile and benzonitrile yielding 100% protonated parent species when reacting with H3O+ [40]. 

Amides, coco, N-[3-(dimethylamino) propyl]. See Cocamidopropyl dimethy-lamine... 

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