Trimethylamine, purification

If photochemical apparatus is not available, the cycloisomerization reaction can be conducted using trimethylamine N-oxide to promote oxidative decarbonylation of molybdenum hexacarbonyl in a mixture of EtjN and EtgO, followed by addition of 1-phenyl-3-butyn-1-ol (1). In the submitters hands, this procedure required somewhat higher loading of molybdenum hexacarbonyl, and purification of the 2-phenyl-2,3-dihydrofuran (2) product required silica gel chromatography. 

All reactions are carried out under N2 atmosphere with use of standard Schlenk techniques. Solvents are dried appropriately before use. Ceo (99.5%, Southern Chemical Group, LLC) is used without further purification. Anhydrous trimethylamine A-oxide (mp 225-230°C) was obtained from Me3N0-2H20 (98%, Aldrich) by sublimation (3 times) at 90-100°C under vacuum. 

The checkers used Fisher Scientific basic alumina, Brockman activity I, 80-200 mesh. Neutral alumina and silica gel have also been used. Basic alumina minimizes the potential hazards of hydrolysis or proton-catalyzed isomerization of the carbon-carbon double bond in susceptible enol ethers. Gaseous trimethylamine has also been added to the eluent to minimize these problems during purification. 

The residue from sublimation of the complex with dioxane is explosive, and the complex should not be dried by heating. The trimethylamine complex may also explode on sublimation [1]. Triethynylaluminium or its complex with diethyl ether may decompose explosively on heating. Sublimation is not therefore advised as a purification method [2]. See other METAL ACETYLIDES... 

Trimetaphosphimic acid, 6 79 Trimethylamine, coordination compounds with boron fluoride and chloride, 5 26, 27 purification of, 2 159 Trimethylamine-sulfur dioxide, 2 159... 

Strong-base ion-exchange fibrous materials (SBF) were tested as sorbents for purification of air from acid impurities exemplified by S02- The SBF exchangers were prepared by amination with the trimethylamine of chloromethylated polystyrene grafted on polypropylene fibres. 

Dimethyl sulfoxide-Sulfur trioxide [1, 309, before references]. The combination of DMSO and sulfur trioxide, in the form of the pyridine complex, in the presence of trimethylamine oxidizes primary and secondary alcohols in good yield to aldehydes and ketones, respectively.55 The reaction usually is complete within minutes and the products are isolated by acidification and precipitation with water. The reagent also oxidizes allylic alcohols to the corresponding a,fi-unsaturated carbonyl compounds. One advantage over the DMSO-DCC method is that the elaborate purification required when dicyclohexylurea is a product can be dispensed with. Testosterone, with a 17/3-hydroxyl group, was oxidized toA -androstene-3,17-dione very rapidly the 17-epimer required a period of 35 min. 

It was observed experimentally that by increasing the number of PO units per chain derived from one hydroxyl group there are obtained not only lower hydroxyl numbers but the viscosities of the resulting aminic polyols decrease significantly. The extension of the chains with PO is possible only after the addition of a catalyst, such as KOH, NaOH, low hindered tertiary amines or imidazoles. Utilisation of KOH and NaOH as catalysts needs a purification step. Using a low hindered amine as catalyst (trimethylamine, dimethyethanolamine, dimethylcyclohexylamine) the resulting polyols do not need any purification. 

Benjakul, S., Visessanguan, W., and Tanaka, M. 2003b. Partial purification and characterization of trimethylamine-N-oxide demethylase from fizardfish kidney. Comparative Biochemistry and Physiology 135B 359-371. 

Analogous Knoevenagel reaction is an example of use of gaseous reagents in ball mill. Ball milling of aromatic aldehydes with cyanoacetamide were too slow at room tanperature and required a basic catalyst such as gaseous trimethylamine to achieve full conversion without the need for purification (Scheme 2.49). In classical melt conditions (150-170°C) quantitative yields were obtained within 1 h. 

Whereas further purification of 6 was unsuccessful because of the lability in air and moisture, the crystals gave the satisfactory spectroscopic data to indicate the structure. Although the Si-H coupling constants for anionic pentacoordinate hydridosilicates have never been reported, the value ( Jsi.nl = 253.5 Hz) is quite reasonable in comparison with the value reported for the (tetrafluoroethyl)silane-trimethylamine complex (246 Hz), indicative of the equatorial location of the hydrido ligand which is bonded to the sp hybridized orbital on silicon. 

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