Amidine Hydrochlorides Research Articles

Copper-Mediated Sequential C–N and N–N Bond Formation: Facile Synthesis of Symmetrical 1,2,4-Triazoles

Via a one-pot process, catalyzed by Cu(OAc)₂, a series of 3,5-disubstituted 4<i>H</i>-1,2,4-triazoles was conveniently and efficiently synthesized by using low-toxicity, stable, readily available, inexpensive amidine hydrochloride.

Synthesis of a series of carbon-14 labeled tetrahydropyrido[4,3-d]pyrimidin-4(3H)-ones

A series of tetrahydropyrido[4,3-d]pyrimidin-4(3H)-ones labeled with carbon-14 in the 2-position of pyrimidinone moiety were prepared as part of a 3-step sequence from benz[amidino-(14) C]amidine hydrochloride as a key synthetic intermediate.

Copper-Catalyzed Sequential N-Arylation and Aerobic Oxidation: Synthesis of Quinazoline Derivatives

A novel and efficient copper-catalyzed cascade method for the synthesis of quinazoline derivatives has been developed. The protocol uses readily available substituted (2-bromophenyl)methylamines and amidine hydrochlorides as the starting materials, inexpensive CuBr as the catalyst, and economical and environment friendly air as the oxidant, and the corresponding quinazoline derivatives were obtained in moderate to good yields. The procedure underwent sequential intermolecular N-arylation, intramolecular nucleophilic substitution and aerobic oxidation.

ChemInform Abstract: Synthesis of Benzimidazoles by Cu2O‐Catalyzed Cascade Reactions Between o‐Haloaniline and Amidine Hydrochlorides.

Abstract An efficient Cu 2 O-catalyzed method for the synthesis of benzimidazole derivatives from amidine hydrochlorides and o -haloaniline has been developed. The cascade C–N coupling and intramolecular transamination reaction provided benzimidazole derivatives in high yields up to 90%.

Synthesis of polyhalo 2-aryl-4-aminoquinazolines and 3-amino-indazoles as anti-cancer agents

A series of polyhalo 2-aryl-4-aminoquinazolines 3a–3n were prepared by reacting polyhalo isophthalonitriles 1a–1c with amidine hydrochlorides under basic conditions with good yields (70–93%). Also, through the reaction of polyhalo isophthalonitriles 1a–1c with hydrazines to give novel polyhalo 3-aminoindazoles 5 and 7 with moderate yield (70–87%). The anticancer activities of compounds 3, 5 and 7 were evaluated in vitro against human cell lines SKOV-3, HeLa, U2-OS, A549, and MCF-7. Some compounds showed excellent growth inhibitory activities and 3a was found to be the most potent derivative, with an IC50 value lower than 3.86 μg mL−1 against the five tumor cell lines. The mechanism of action of representative compound 5b was investigated in the HCT116 colorectal cancer cell line. It was shown that 5b reduced cell viability of cancer cells in a time and concentration dependent manner. Cells treated with 5b accumulate in the G2/M phase of the cell cycle and finally go into apoptosis.

Synthesis of benzimidazoles by Cu2O-catalyzed cascade reactions between o-haloaniline and amidine hydrochlorides

An efficient Cu2O-catalyzed method for the synthesis of benzimidazole derivatives from amidine hydrochlorides and o-haloaniline has been developed. The cascade C–N coupling and intramolecular transamination reaction provided benzimidazole derivatives in high yields up to 90%.

ChemInform Abstract: One‐Step Synthesis of 2‐Amino‐5H‐pyrimido[5,4‐b]indoles, Substituted 2‐(1,3,5‐Triazin‐2‐yl)‐1H‐indoles, and 1,3,5‐Triazines from Aldehydes.

Anefficientone-stepsynthesisof2-amino-5H-pyrimido[5,4-b]indoles through a copper-catalyzed cascade reaction between 3-haloindole-2-carbaldehydes and guanidine hydrochloride is described. In contrast, the base-mediated reactions of either 3-haloindole-2-carbaldehydes or substituted indole-2-carbaldehydes with substituted amidine hydrochlorides in DMSO result in the formation of 2-(1,3,5-triazin

Microwave‐Assisted Solvent‐Free Synthesis of Highly Functionalized Pyrimidine Derivatives

We here described an efficient method for the synthesis of a series of highly functionalized pyrimidines via the addition and condensation reaction of ketene dithioacetals with guanidine carbonate or amidine hydrochlorides by microwave irradiation under solvent‐free conditions in the absence of a catalyst, giving the products with good yields (79–98%).

One‐Step Synthesis of 2‐Amino‐5H‐pyrimido[5,4‐b]indoles, Substituted 2‐(1,3,5‐triazin‐2‐yl)‐1H‐indoles, and 1,3,5‐Triazines from Aldehydes

AbstractAn efficient one‐step synthesis of 2‐amino‐5H‐pyrimido[5,4‐b]indoles through a copper‐catalyzed cascade reaction between 3‐haloindole‐2‐carbaldehydes and guanidine hydrochloride is described. In contrast, the base‐mediated reactions of either 3‐haloindole‐2‐carbaldehydes or substituted indole‐2‐carbaldehydes with substituted amidine hydrochlorides in DMSO result in the formation of 2‐(1,3,5‐triazin‐2‐yl)‐1H‐indole derivatives in one step in excellent yields. Studies toward exploring the utility of the method demonstrate that even substituted benzaldehydes undergo a similar reaction to efficiently yield 2,4,6‐trisubstituted 1,3,5‐triazines. A plausible mechanism for the formation of substituted 1,3,5‐triazines identifies the role of DMSO as an oxidant during the reaction.

Easy and efficient one-pot synthesis of pyrazolo[1,5-c]quinazolines under mild copper-catalyzed conditions

An easy and efficient method has been developed for the synthesis of pyrazolo[1,5-c]quinazolines via one-pot two-step reactions of readily available substituted 1-(2-halophenyl)-3-akylprop-2-yn-1-ones, hydrazine hydrochloride and amidine hydrochlorides under mild conditions, and the corresponding pyrazolo[1,5-c]quinazolines were obtained in good to excellent yields. The novel method affords a new strategy for the construction of diverse and useful poly N-heterocyclic compounds.

One‐Pot Synthesis of Pyrimidines via Cyclocondensation of β‐Bromovinyl Aldehydes with Amidine Hydrochlorides

AbstractA series of pyrimidines were prepared by cyclocondensation of β‐bromovinyl aldehydes with amidine hydrochlorides in the presence of Et3N in excellent yields (74–95%).

Hexaazaphenalene Derivatives: One-Pot Synthesis, Hydrogen-Bonded Chiral Helix, and Fluorescence Properties

Symmetric hexaazaphenalenes (R = phenyl and tert-butyl) have been synthesized by one-pot condensations of corresponding amidine hydrochlorides with tricyanomethanide. The hexaazaphenalenes are linked with each other by a N-H···N hydrogen-bonding interaction in the crystalline states. Interestingly, a planar and achiral tert-butylated derivative was crystallized in a chiral space group with assembly of one-handed helical hydrogen-bonded chains. Hexaazaphenalenyl anions were isolated as air- and water-stable tetraethyl ammonium salts.

Mild and efficient ligand-free copper-catalyzed condensation for the synthesis of quinazolines

Condensation of o-iodobenzaldehydes 1a _c with amidine hydrochlorides 2a _p under ligand-free copper-catalyzed Ullmann N-arylation conditions afforded the corresponding quinazolines 3a– r in good to excellent yields.

ChemInform Abstract: Copper‐Catalyzed Synthesis of Benzimidazoles via Cascade Reactions of o‐Haloacetanilide Derivatives with Amidine Hydrochlorides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Copper‐Catalyzed Synthesis of Primary Arylamines via Cascade Reactions of Aryl Halides with Amidine Hydrochlorides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Copper-Catalyzed Synthesis of Benzimidazoles via Cascade Reactions of o-Haloacetanilide Derivatives with Amidine Hydrochlorides

We have developed an efficient method for the synthesis of benzimidazoles via cascade reactions of o-haloacetoanilide derivatives with amidine hydrochlorides. The protocol uses 10 mol % CuBr as the catalyst, Cs2CO3 as the base, and DMSO as the solvent, and no ligand is required. The procedure proceeds via the sequential coupling of o-haloacetoanilide derivatives with amidines, hydrolysis of the intermediates (amides), and intramolecular cyclization with the loss of NH3 to give 2-substituted 1H-benzimidazoles.

Copper-Catalyzed Synthesis of Primary Arylamines via Cascade Reactions of Aryl Halides with Amidine Hydrochlorides

We have developed an efficient method for the synthesis of primary arylamines from aryl halides using amidine hydrochlorides as the ammonia surrogates. The protocol uses 10 mol % CuI as the catalyst, 20 mol % L-proline as the ligand, Cs2CO3 as the base, and DMF as the solvent and proceeds the sequential coupling of aryl halides with amidine hydrochlorides and hydrolysis of intermediates to give the target products. This is a convenient, inexpensive, and practical approach to primary arylamines.

Synthesis of 2-Substituted Pyrimido[5,4-b]indolizine Derivatives from Acetates of Baylis-Hillman Adducts

-Novel tricyclic heterocycle pyrimido[5,4-b]indolizine derivatives 1 were synthesized conveniently in two steps. The key intermediates 2-substituted 5-[(pyridin-2-yl)methyl]pyrimidin-4(3H)-ones 2 were obtained by facile cyclization of the acetate of Baylis-Hillman adduct 3 and various amidine hydrochlorides 4 in the presence of sodium ethoxide. Treatment of 5-[(pyridin-2-yl)methyl]pyrimidin-4(3H)-ones 2 with phosphoryl chloride by reflux afforded fused 2-substituted pyrimido[5,4-b]indolizines 1 in high yield.

Highly efficient copper-catalyzed cascade synthesis of quinazoline and quinazolinone derivatives

We have developed a general and highly efficient copper-catalyzed method for synthesis of quinazoline and quinazolinone derivatives, the target products were obtained in good to excellent yields via cascade reactions of amidine hydrochlorides with substituted 2-halobenzaldehydes, 2-halophenylketones, or methyl 2-halobenzoates, and the method is of simple, economical and practical advantages.

Traceless solid phase synthesis of 2-substituted pyrimidines using an 'off-the-shelf' chlorogermane-functionalised resin.

The parallel solid phase synthesis of an 18-member library of 2-substituted pyrimidines is described using a chlorogermane-functionalised resin. The success of the key Pinner-type condensations between a resin-bound enaminone and an array of amidine hydrochlorides highlights the stability of arylgermane linkers (cf. arylsilanes) towards strongly basic/nucleophilic conditions.