Hydroxy-, derivatives quaternization

The B—H derivatives were prepared by reduction of butyl esters with LAH in the presence of aluminum chloride (equation 48). Whereas B-hydroxy derivatives like (409a) were stable against hydrochloric acid and 2N sodium hydroxide, the B—H derivative (413) reacted slowly with water and alcohols under evolution of hydrogen, forming the B—OR compounds. With acid chlorides, quaternization with formation of the (V-acyl derivatives occurred. 

A number of quinoxalines carrying substituents in the benzene ring base have been quaternized, including 5-ethoxy,6-methyl, 6-chloro, and some 2-phenyl derivatives, but in none of these cases has the position of quatemization been ascertained. 5-Hydroxy-quinoxaline gives a methiodide which can still form metal complexes, indicating that salt formation occurred on N-1. ... 

On boiling the methiodide with 70% sulfuric acid an N-methyl-oxo derivative was obtained, and this in turn gave 3-amino-2-phenyl-quinoline, methylamine, and ammonia on fusion with soda lime. The bulk of the evidence therefore favors quaternization at N-2 (cf, 154), in which case the acid-hydrolysis product is 155. Quaternization at N-2 would be expected because of the steric influence of the 10-phenyl group and the influence of the 4-amino group (cf. 4-hydroxy-pyridazine ) in the pyridazine-type ring, although the partial double-bond character of that ring is probably different from that in pyridazine itself. 

A method conceptually related to Scheme 131 requires that one or both of the carbonyl groups shown in (266) be present as the oxime derivative, with cyclization leading to the 2-iV-oxide (269 Scheme 132). In actual practice (66JOC941) it was found that two of the proposed intermediates (Table 16, examples 7 and 9) cyclized spontaneously under quater-nization conditions to afford the aromatic 2-azaquinolizinium AT-oxide derivative directly. In another example (Table 16, example 4) (71JCS(C)86l) intramolecular addition occurred during quaternization, but the product, a 3-hydroxy-3,4-dihydro-2-azaquinolizinium derivative, did not lose water spontaneously to form the aromatic system until heated with acid. 

The fully aromatic diquaternary system 81 is prepared by acid ring closure of the salt (79) obtained by quaternization of 1,10-phen-anthroline with bromoacetaldehyde followed by dehydration of the resulting hydroxy diquaternary salt (80) with thionyl chloride.310,311 The salt 81 is unstable in aqueous solution above a pH of about 5.0. In the pH range 3.3-5.0 it is reduced by a one-electron transfer to the corresponding radical cation at a potential (E0) of —0.12 volt.311 Its reduction in dimethylformamide solution has also been studied.15,307 Substituted derivatives of 81 have been prepared.312... 

Aminocyclopropanes bearing a suitable leaving group in the a-position have been extensively used for the synthesis of further aminocyclopropane derivatives. Thereby, an amino, a hydroxy, a methoxy or a trimethylsilyloxy moiety in 375 could be displaced by other substituents leading to 377. Acidic medium or a large excess of the nucleophile (as in solvolysis reactions) or activation of the leaving group (e.g. by quaternization of an amino... 

Gelatins, hydrolysates, tnyristoyl derivs.. See Myristoyl hydrolyzed collagen Gelatins, polymers with keratin hydrolyzates and L-lysine, hydroxy-N,N,N- trim-ethyl-1-propanaminium chloride quaternized, reaction prods, with isos-tearoyl chloride, compds. with 2-amino-2-methyl-1-propanol. See AMP-isostearoyl gelatin/keratin amino acids/lysine hydroxypropyltrimonium chloride... 

Alkylation and Quaternization.—4-Bromo-5-hydroxy-3-methylisothiazole is O-methylated by diazomethane in contrast, 3-hydroxy-5-phenylisothiazole is N-methylated, and equimolar mixtures of the O- and N-methyl derivatives are produced from 3-hydroxyisothiazoles. N-Methylation also prevails when 3-hydroxy-4,5-diphenylisothiazole is alkylated by dimethyl sulphate. ... 

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