A novel alkylation procedure using MW irradiation for the synthesis of 1,2,3-trisubstituted 1,4,5,6,7,8-hexahydro-1,3-diazocinium salts from their corresponding 1,2-diaryldiazocines

Ultrasound Promoted Synthesis and Antimicrobial Evaluation of Novel Seven and Eight-Membered 1,3-Disubstituted Cyclic Amidinium Salts

“…Unlike other medium size cyclic amidinium salts [53] the compounds were generally isolated as hygroscopic solids, melting above 100˚ and, therefore, they are not ionic liquids. This would be related with the structural symmetry of salts 1.…”

Synthesis and properties of seven- to nine-membered ring nitrogen heterocycles. Cyclic amidines and cyclic amidinium salts

“…However, when the aryl group of the N-arylalkylenediamine is not substituted or when it is substituted with electron donor or slightly electron withdrawing groups, the reaction with acyl chlorides under Schotten-Baumann conditions led to the corresponding N,N'-diacyl derivatives. 32 Selective monoacylation was achieved using aliphatic carboxylic acid anhydrides working at 0 o C in a biphasic system (Cl 3 CH/aqueous Na 2 CO 3 ) 75 or working in homogeneous phase with DCM as solvent and TEA as acceptor of hydrogen chloride at -10 o C (55-60%). 32 Another suitable synthetic strategy to obtain the precursor aminoamides 20 involves the synthesis of N-4halobutyl or N-5-halopentylbenzamides 22 as key synthetic intermediates and subsequent reaction with amines (Method B-2).…”

“…32 Selective monoacylation was achieved using aliphatic carboxylic acid anhydrides working at 0 o C in a biphasic system (Cl 3 CH/aqueous Na 2 CO 3 ) 75 or working in homogeneous phase with DCM as solvent and TEA as acceptor of hydrogen chloride at -10 o C (55-60%). 32 Another suitable synthetic strategy to obtain the precursor aminoamides 20 involves the synthesis of N-4halobutyl or N-5-halopentylbenzamides 22 as key synthetic intermediates and subsequent reaction with amines (Method B-2). Attempts to obtain the haloalkylamides 22 by acylation of the corresponding haloalkylamines in basic medium have failed, because in such reaction medium intramolecular aminolysis occured.…”

“…The reaction with alkyl halides leads to the corresponding resonance-stabilised cyclic amidinium salts 24. [31][32][33]35 Since the reaction is a typical S N 2 displacement, it is adequate for the introduction of primary alkyl groups (Scheme 25).…”

“…More recently, some of these compounds have been investigated as N-methyl-D-aspartate (NMDA) receptor antagonists, 27 dopamine D4 receptor 28 and muscarinic agonists, 29 as well as for the prophylaxis and protection of human skin against premature aging. 30 Seven-and eight-membered substituted cyclic amidines are also useful precursors for the synthesis of heterocyclic ring systems as amidinium salts by alkylation, [31][32][33] and selectively substituted alkylenediamines by either reduction or alkaline hydrolysis. [34][35][36] In recent years, cyclic amidinium salts (CAS) with a fully saturated backbone (II) have attracted a great deal of attention.…”