Alkyl salts

Sulfates —0—SO2—0— Primary alkyl salts Secondary alkyl salts 1415-1380 (s) 1200-1185 (s) 1315-1220 (s) 1140-1075 (m) 1270-1210 (vs) 1075-1050 (s) Electronegative substituents increase frequencies. Strongly influenced by metal ion Doublet both bands strongly influenced by metal ion... 

Pyrazoles and imidazoles with free NH groups are readily alkylated, e.g. by Mel or Me2S04. A useful procedure is to use the alkyl salt of the azole in liquid ammonia (80AHC(27)241). However, alkylation can also occur under neutral conditions, particularly with imidazoles. 

Very large solvent effects arc also observed for systems where the monomers can aggregate either with themselves or another species. For example, the apparent kp for polymerizable surfactants, such as certain vinyl pyridinium salts and alkyl salts of dimethylaminoalkyl methacrylates, in aqueous solution above the critical micelle concentration (cmc) are dramatically higher than they are below the cmc in water or in non-aqueous media.77 This docs not mean that the value for the kp is higher. The heterogeneity of the medium needs to be considered. In the micellar system, the effective concentration of double bonds in the vicinity of the... 

The orthoamide 40 reacted smoothly with 4-alkoxybenzyl bromide 208 to give the alkylated salt triazamacrocycle 209 <2000CC955> in almost quantitative yield (Scheme 32). ... 

It was demonstrated that benzyl halides can smoothly alkylate salts of particular primary (15) and secondary (16) AN (Scheme 3.6, Eq. 4). 

In the course of theoretical calculations discussed above (Section 11.21.2, Table 1), heats of formation of alkylated salts have been computed <2000ARK259>. The most favourable AA values have been obtained for the N(l)-Me and N(2)-Me salts, and this result was in entire agreement with the experimentally observed site of alkylations (i.e., with formation of 14 and 15 as shown in Scheme 4, Section 11.21.5.2.1). 

Salts of O-alkyldithiocarbonatcs ( xanthates ) are hazardous as dusts, forming explosive suspensions in air. The lower-alkyl salts are claimed to be explosive in the solid state when dry [1]. Explosions reported when drying hydrated xanthate salts are probably the consequence of release of carbon disulphide to form an inflammable atmosphere of very low autoignition temperature in the oven [2], Xanthate esters are thermally unstable by a variety of eliminations and rearrangements, all distinctly exothermic and many evolving extremely flammable gases and vapours. Free xanthic acids, which may be isolated on acidification, decompose autocatalytically and perhaps explosively [3],... 

Treatment of dibenzothiophene with alkyl halides in the presence of silver tetrafluoroborate or triaryloxonium tetrafiuoroborate has recently been shown to yield the corresponding 5-alkyl salts of type g0 96,359 Compounds thus prepared include 5-methyl- (93%), 5-ethyl-(98%), and 5-isopropyldibenzothiophenium tetrafiuoroborate (14%). The products were thermally unstable, reverting to dibenzothiophene, although the corresponding perchlorates were more stable. 5-Methoxy-... 

Alkyl and acyl halides react directly with quinoline to give A-alkyl-or A-acylquinolinium salts (Scheme 3.4). Whereas the A-alkyl salts are stable and can often be isolated as crystalline solids, the A -acyl analogues are unstable and undergo rapid hydrolysis in moist air or in aqueous solution. 

Alkylation of W -(5-acetyl-67/-l,3-thiazin-2-yl)-WA -dimethylformamidine 113 with 2-bromo-l-(4-bromophenyl)etha-none resulted in attack at the nitrogen in the ring and formation of the N-alkylated salt (Scheme 4). The latter was not isolated but treated directly with 2 equiv of base to give, after loss of dimethylamine, the imidazo[2,l-/ ][l,3]thia-zine 114 <2003EJ0421>. 

Quinolinium salts react similarly to pyridinium compounds when oxidized. N-Alkylated salts 142, for example, yield only 2-quinolones 143 after Decker oxidation. 4-Quinolones 144 cannot be isolated (1892CB443 70HCA1903). 

The oxazoles and their derivatives have played a variety of fascinating roles in the preparation of new molecular systems. Much of this chemistry stems from their ability to serve as diene components (azabutadiene equivalents) in reactions with a variety of dienophilic agents, to undergo nuclear metallation, to activate attached aryl or alkyl groups to deprotonation (thus functioning as masked aldehydes, ketones or carboxylic acid groups), and to serve as useful electrophiles on conversion to AT-alkylated salts. 

Catalysts of greater thermal stability have also been used, such as IV-alkyl salts of 4-dialkylamino-pyridines (48)162 and tris(polyoxaheptyl)amine (TDA-1).161... 

Sulfates — O—S02—O (continued) Secondary alkyl salts 1270-1210 (vs) Doublet both bands strongly... 

Table 2. Estimated number of possible chemicals that can be derived from the definitions for scheduled chemicals contained in the Annex on Chemicals of the CWC not counting corresponding protonated or alkylated salts, where this is applicable...

A little more is known about the quaternization of substituted 1,2,4-triazines, but alkylation sites are frequently uncertain (63JCS1628). The observation that 1-alkyl salts are red while the 2-alkyltriazinium iodides are colorless is of some assistance. The isolation of the 3-dimethylamino... 

O II XO J cc + X 0 1 DC reductive alkylation salt-free Williamson ether synthesis r-ch2-o-r Pd/C... 

If LiCH(SiMe3)2 is treated directly with UCl3(THF)3 in a salt-elimination reaction the alkylate salt [(THF)3Li-Cl-U CH(SiMe3)2 3] is obtained. 

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