Salts, hydrolysis inner salt

The papaver alkaloid Narcotoline (265) can be converted into the yellow colored Cotarnoline (267) on hydrolysis which adopts a zwitterionic ground state (56MI1, 57MI1) (Scheme 87). The corresponding dihydro derivative was also identified in nature. The UV spectrum of the zwitterionic Tarkonine (268), which forms red crystals from acetone, is shifted bathochromically in comparison to the chloride. Tarkonine is a very weak base (pA b = 9.58), which is well in accord with the formation of an inner salt, and Cotarnoline (267) is a stronger base than Tarkonine (268) (pA b = 9.15). The pK values are larger than 13 (66MI3). The methylated derivative of Narcotoline is Narcotine (266). 

The above procedure describes the only known preparation of the inner salt of methyl (carboxysulfamoyl)triethylammonium hydroxide and illustrates the use of this reagent to convert a primary alcohol to the corresponding urethane.2 Hydrolysis of the urethane would then provide the primary amine. The method is limited to primary alcohols secondary and tertiary alcohols are dehydrated to olefins under these conditions, often in synthetically useful yields.2... 

Catalytic reduction of ll-mercaptopyrido[l,2-6]cinnolin-6-ium hydroxide inner salt (41) over Raney Ni yielded 2-(2-aminobenzyl)pyridine (74JHC125). When a 36-h reaction period was applied in the hydrolysis of 42, 1-benzylisoquinoline was obtained (83JOC1084). 

Alkylation of ll-mercaptopyrido[l,2-h]cinnolin-6-ium hydroxide inner salts (e.g., 41) with ethyl bromoacetate gave ll-(ethoxycarbonylmethyl(thio derivatives 64 (R = H), which could be hydrolyzed to the ll-(carboxy-methyl)thio derivative or back to the starting compound 41 (74JHC125). Hydrolysis of the ll-bis(methoxycarbonyl)methylene 66 (R = H), and 2-cyano derivatives of 17 (R = H) in boiling HCl afforded 11-methyl and 2-carboxylic acid derivatives, respectively (74JHC125). The 2-nitro derivative of 17 (R = H) was reduced to the 2-amino derivative over Pd/C with NaBH4 in aqueous methanol, and the 2-amino group was acylated with acetic anhydride at 100°C. 

Hydrolysis of the inner salts (33) of anhydro 6-aryl-2-methyl-3-methylthio[l,2,4]triazolo[4,3-ft][l,2,4]triazolium hydroxides with alkali results in the displacement of the methylthio group and the formation of the 77/-[l,2,4]triazolo[4,3-(>][l,2,4]triazol-3(2//)-ones (34) (Equation (4)) <85BCJ735>. 

Reacting nitrogen-stabilized a-carbenium dithioates 110 and 111 (inner salts) with electrophiles yields the a-carbenium dithioesters 112 and 113, respectively, in high yields, as shown in Scheme 23 [64] and Scheme 24 [65]. Hydrolysis of 112 and 113 gives a-oxo dithioates 114 and 115, respectively. In the case of imidazolidinium dithioate 117, prepared from the inner salt 116, the hydrolysis is followed by intramolecular cyclization to give a 28% yield of 3-thioxo piperazin-2-one 118 (Scheme 25) [64]. The alkylation of p-carbenium dithioate 119 proceeds similarly (Scheme 26) [66]. 

The chemical shifts of the phosphorous atoms are very sensitive to changes in the chemical surroundings. To avoid hydrolysis the pH value has to be held between 5 and 9, which is the pKs region of phospholipids. Even small changes in the pH causes shifts of 0.5-2 ppm. The chemical shift of PC is the most independent of pH because of the inner salt structure phosphatidic... 

When neutral or acid phenolphthalein, a lactone inner anhydride which is colorlessj is treated with sodium hydroxide to just alkaline reaction, hydrolysis first takes place yielding the carbinol. This is then neutralized by the alkali yielding a di-sodium salt, one sodium entering the carboxyl group and the other entering one of the phenol... 

Morin, the coloring matter of fustic, is 3,5,7,2, 4 -pentahydroxy flavone (I). Its alcohol solutions react with aluminum salts in neutral or acetic acid solution to give an intense green fluorescence in daylight and ultraviolet light. The fluorescence is due to the formation of a colloidally dispersed inner complex aluminum salt of morin with the probable structure (II), or to an adsorption compound of morin with alumina. Beryllium, indium, gallium, thorium and scandium salts also form fluorescent compounds with morin. The pH of the system has much influence in these reactions. The only metal ion whose reaction with morin is independent of pH is Zr+ or its hydrolysis product (compare page 519). 

The zirconium alizarinate does not correspond precisely to an inner complex zirconium salt of alizarin rather, it is the hydrosol of a violet zirconium-alizarin lake, i.e. a colored adsorption compound of hydrolysis products of aqueous zirconium salt solutions with alizarin (compare Vol. II page 347). 

---