Alkyl Bromoacetates Research Articles

A green and efficient synthesis of alkyl 2-((5-hydroxy-1H-pyrazole-4-carbonothioyl)thio)acetates via a one-pot, solvent-free reaction

A green and efficient synthesis of alkyl 2-((5-hydroxy-1H-pyrazole-4-carbonothioyl)thio)acetates is described. The method involves a one-pot, solvent-free reaction of pyrazolone derivatives, carbon disulfide, and alkyl bromoacetates in the presence of triethylamine. The crude products were readily purified by simple water washing followed by recrystallization from diethyl ether. The structures of the synthesized pyrazole-4-carbonothioyl-thio-acetate derivatives were confirmed by IR, 1H NMR, 13C NMR, and mass spectrometry.

Retracted: Synthesis, Characterization, and Surface Activities of Polymeric Cationic Thiol Surfactants in Aqueous Medium

AbstractA series of cationic polyurethane surfactants [PQ8‐18] were synthesized by the reaction of alkyl bromoacetate (namely: octyl‐, decyl‐, dodecyl‐, tetradecyl‐, hexadecyl‐, and octadecyl bromoacetate) as quaternizing agents and modified polyurethane contains tertiary amine species. Modified polyurethane was prepared by the reaction of toluene diisocyanate (TDI) and triethanol amine monomercaptoacetate. The chemical structures of the prepared surfactants were confirmed using elemental analysis, Fourier transform infrared spectroscopy (FTIR), and Proton nuclear magnetic resonance (1H NMR) spectroscopy. The molecular weight measurements of the prepared polymers showed that the segments of each polymer contain average 10 units of the urethane‐triethanol amine mercaptoacetate. The surface activities of the prepared surfactants including: surface tension (γ), effectiveness ( πcmc), concentration at micelle formation (CMC), efficiency (Pc20), maximum concentration at the interface (Γmax), and the average area occupied by each surfactant molecule at the interface at equilibrium ( A min) of surfactants solutions were established at 25°C. The surface tension and the critical micelle concentration values of the prepared surfactants were gradually decreased by the gradual increase of their alkyl chain length. The prepared cationic surfactants showed efficient activity as inhibitors for dissolution of carbon steel in an acidic medium and also as a biocide against the growth of bacteria, fungi, and yeast.

One-Pot Assembly of Alkyl [(5-Amino-1H-pyrrol-2-yl)sulfanyl]-acetates from Propargylamines, Isothiocyanates, and Alkyl Bromoacetates

Methyl and tert-butyl 2-{[5-(diethylamino)-1-methyl-1H-pyrrol-2-yl]sulfanyl|acetates have been synthesized in one preparative stage from accessible N,N-diethylprop-2-yn-1-amine, methyl isothiocyanate, and methyl 2-bromoacetate.

Synthesis, Surface Activities and Anti-Bacterial Activity of (Copper and Nickel) Nanoparticles Stabilized by Cationic Thiol Polyurethane Surfactants

A series of cationic polyurethane surfactant [PQ14, PQ16 and PQ18] were synthesized by the reaction of alkyl bromoacetate (namely: tetradecyl-, hexadecyl- and octadecyl bromoacetate) as quaternizing agents and modified polyurethane contains tertiary amine species. Modified polyurethane was prepared by the reaction of toluene diisocyanate (TDI) and Triethanol amine mono mercaptoacetate. Grinding method is used to synthesize copper and nickel nanoparticles which stabilized by Cationic Thiol polyurethane surfactants. The chemical structures of the prepared surfactants were confirmed using elemental analysis, FTIR, UV and ¹H-NMR spectroscopy. The molecular weight measurements of the prepared polymers showed that the segments of each polymer contain average 10 units of the urethane-Triethanol amine mercaptoacetate. The surface activities of the prepared surfactants including: surface tension (g), effectiveness (π_cmc), concentration at micelle formation (CMC), efficiency (Pc₂₀), maximum concentration at the interface (G_max), average area occupied by each surfactant molecule at the interface at equilibrium (A_min) of surfactants solutions were established at 25°C. The surface tension and the critical micelle concentration values of the prepared surfactants were gradually decreased by the gradual increase of their alkyl chain length. Antimicrobial activity of the synthesized cationic surfactants and their nanostructure with copper and nickel nanoparticles were evaluated against pathogenic bacteria and fungi. The antimicrobial activity showed the enhancement in the antimicrobial activity of the synthesized cationic surfactants in the nanostructures form.

Stereoisomers of N-substituted soft anticholinergics and their zwitterionic metabolite based on glycopyrrolate--syntheses and pharmacological evaluations.

In this study, isomers of two N-substituted soft anticholinergics based on glycopyrrolate, SGM (PcPOAGP_NA.Me) and SGE (PcPOAGP_NA.Et) [3'-(2-cyclopentyl-2-phenyl-2-hydroxyacetoxy)-1'-methyl-1'-alkoxycarbonylpyrrolidinium bromide] and their zwitterionic metabolite, SGa (PcPOAGP_NA.H) [3'-(2-cyclopentyl-2-phenyl-2-hydroxyacetoxy)-1'-methyl-1'-carboxymethylpyrrolidinium inner salt] were synthesized and their pharmacological activities were evaluated in vitro and in vivo. The isomers of SGM and SGE were synthesized with both optically pure methyl-cyclopentylmandelate and 3-hydroxy-N-methylpyrrolidine. Trans-esterification followed by quarternization with alkyl bromoacetate gave four isomers of SGM or SGE with the nitrogen chiral center unresolved (2R3'S-SGM, 2R3'R-SGM, 2S3'S-SGM, 2S3'R-SGM or 2R3'S-SGE, 2R3'R-SGE, 2S3'S-SGE, 2S3'R-SGE). The hydrolysis of these four isomers followed by HPLC separation resulted in eight fully resolved isomers of SGa (2R3'R1'R, 2R3'S1'R, 2R3'R1'S, 2R3'S1'S, 2S3'R1'R, 2S3'S1'R, 2S3'R1'S, and 2S3'S1'S). Pharmacological activities were assessed by using in vitro receptor-binding assay and guinea pig ileum pA2-assay, and by evaluating the in vivo rabbit mydriatic effects. Results were compared to those obtained with conventional anticholinergic agents, such as glycopyrrolate, N-meythylscopolamine, and tropicamide, as well as those obtained with previously prepared racemic mixtures and 2R isomers. Receptor binding pKi values at cloned human muscarinic receptors (M1-M4 subtypes) were in the 6.0-9.5 range for the newly synthesized SGM and SGE isomers, and in the 5.0-8.6 range for the SGa isomers. In all cases, 2R isomers were significantly more active than 2S isomers (27 to 447 times for SGM isomers, and 6 to 4467 times for SGa isomers). Among the four SGM isomers with unresolved 1' (N) chiral center, the 3'R isomers were more active than the corresponding 3'S isomers (1.5-12.9 times), whereas, among the SGa isomers, the 3'S isomers were not always more active than the corresponding 3'R isomers indicating that activity determined based on configuration at chiral center 3' is significantly affected by the configuration of the other two chiral centers, 2 and 1'. Among the completely resolved eight SGa isomers (all three chiral centers resolved), 1'S isomers were always more active than the corresponding 1'R isomers (1.8-22.4 times). Results also indicate that some isomers showed good M3/M2 muscarinic-receptor subtype-selectivity (about 3-5 times), and 2R and 3'S were the determining configurations for this property. Guinea pig ileum assays and rabbit mydriasis tests on SGa isomers further confirmed the stereospecificity. In rabbit eyes, some 2R-SGa isomers showed mydriatic potencies similar to glycopyrrolate and exceeded tropicamide, but their mydriatic effects lasted considerably shorter, and they did not induce dilation of the pupil in the contralateral, water-treated eye. These results indicate that these compounds are locally active, but safe and have a low potential to cause systemic side effects. The pharmacological potency of the eight SGa isomers was estimated as 2R3'S1'S approximately equal to 2R3'R1'S approximately equal to 2R3'S1'R > 2R3'R1'R > 2S3'R1'S > 2S3'S1'S approximately equal to 2S3'R1'R > 2S3'S1'R (p < 0.05). The stereospecificity and M3/M2 muscarinic-receptor subtype-selectivity of soft anticholinergics, SGM, SGE, and SGa have been demonstrated. In agreement with previous results, the potential for their effective and safe use has been confirmed.

Betaine ester-shell functionalized hyperbranched polymers for potential antimicrobial usage: Guest loading capability, pH controlled release and adjustable compatibility

Betaine ester-shell functionalized hyperbranched polyethylenimines (BEHPEI) were synthesized by Menschutkin reaction between per-N-methylated polyethylenimine (MeHPEI) and alkyl bromoacetate. BEHPEI could play dual antimicrobial roles that were, the betaine ester-shell acted as contact-based antibacterial polycations and the drug-loaded BEHPEI could controllably release the drugs due to the cleavage of the betaine ester groups under weak alkaline condition. The BEHPEI exhibited high transport capacities that per gram of BEHPEI could encapsulate 0.24–2.67 g of dyes or drugs. The model drug release experiment employing methyl orange (MO) showed that the drug release of MO-loaded BEHPEI complex occurred slowly in weak alkaline solutions and the release rate was controlled by varying pH, while the complex kept very stable under weak acid condition (pH = 3.0–7.0). BEHPEI generated from long chain alkyl bromoacetate was compatible with organic resins implying the possible usage in antimicrobial fibers and coatings. Another BEHPEI obtained from short-chain alkyl bromoacetate was water soluble and maybe used in lotion formula. The hydrolysis of BEHPEI afforded zwitterionic shell.

New highlights of the syntheses of pyrrolo[1,2-a]quinoxalin-4-ones.

The one-pot three-component reactions of 1-substituted benzimidazoles with ethyl bromoacetate and electron-deficient alkynes, in 1,2-epoxybutane, gave a variety of pyrrolo[1,2-a]quinoxalin-4-ones and pyrrolo[1,2-a]benzimidazoles. The influence of experimental conditions on the course of reaction was investigated. A novel synthetic pathway starting from benzimidazoles unsubstituted at the five membered ring, alkyl bromoacetates and non-symmetrical electron-deficient alkynes in the molar ratio of 1:2:1, in 1,2-epoxybutane at reflux temperature, led directly to pyrrolo[1,2-a]quinoxalin-4-ones in fair yield by an one-pot three-component reaction.

Reaction of (ethoxycarbonylfuryl)methanephosphonates with diethyl carbonate in presence of sodium foil

Reaction of (ethoxycarbonylfuryl)methanephosphonates with diethyl carbonate in presence of sodium foil is studied. It is shown that if the acidifying group is conjugated with the carbanion center of 2-furylmethanephosphonate, addition of the carbanion to the carbonyl group of diethyl carbonate takes place to give 2-furylacetic acid derivatives in high yield. Sodium salts of these CH-acids are synthesized, isolated, and characterized. Their alkylation with alkyl bromoacetates is carried out. If ethoxycarbonyl group is not conjugated with the carbanion center, conversion of starting phosphonate and yield of adduct sharply decreases. Alkyl (2- and 4-ethoxycarbonylfur-3-yl)methanephosphonates immediately after acylation with diethyl carbonate are reduced with sodium-diethyl carbonate system to form alkyl 1-(2- and 4-ethoxycarbonylfur-3-yl)-ethanephosphonates. Formation of intermediate reduction product, the phosphorylated furylacetic aldehyde is also fixed spectroscopically. Simultaneously with the reduction dealkylation of ester group of starting phosphonates and alkyl 1-(3-furyl)ethanephosphonates takes place leading to the carboxylic acid salts. Alkyl (2-methyl-5-ethoxycarbonylfur-3-yl)methanephosphonate does not take part in condensation. It gives only the products of dealkylation under the action of sodium ethylate forming from diethyl carbonate.

3-(2-methylthiopyridin-3-yl)-3-oxopropionic esters

A reaction of alkyl bromoacetates with substituted 3-cyano-2-methylthiopyridines in the presence of zinc dust furnishes 3-amino-3-(2-methylthiopyridin-3-yl)propenoic esters. Their hydrolysis under mild conditions leads to 3-(2-methylthiopyridin-3-yl)-3-oxopropionic esters. The latter were used in the synthesis of pyridine-substituted pyrazolones.

Fluorescent 6‐hydroxy‐ and 6,7‐dihydroxy‐4‐trifluoro‐methylcarbostyrils and formation of o‐carboxymethylated derivatives via o‐succinimide esters

Abstractmagnified imageStepwise demethylation of fluorescent 6,7‐dimethoxy‐3‐trifluoromethylcarbostyrils 5 leads to 6‐hydroxy derivatives 6 and 6,7‐dihydroxyderivative 7. Phenolate formation shifts excitation and emission maxima from 370 and 430 nm to 430 and 480 nm for the anion of 6 and as far as 500 and 580 nm for the dianion of 7. Dependence of fluorescence quantum yield on media and polar structure, varying from 0.02 to 0.51, is discussed. O‐Alkylation of 6 with alkyl bromoacetate yields esters of type 8 in good yield. Reactive succinimidoyl (OSu) esters of type 11 were prepared after saponification to acids 9. With amino acids or their esters, peptides and aminoglucose, linking to labeled derivatives 13 or 15 could be achieved under mild conditions in slightly basic aqueous media.

A Rapid and Highly Efficient One-Pot Methodology for Preparation of Alkyl Oxindolideneacetates

A one-pot solvent free Wittig procedure was suggested for fast and high efficient preparation of alkyl oxindolideneacetates a-h by reaction of isatin derivatives, triphenylphosphine, alkyl bromoacetate and morpholine. Keywords: Isatin, Triphenylphosphine, Alkyl bromoacetate, Wittig reaction, Solvent free conditions, Alkyl oxindolideneacetates

One‐Pot Synthesis of Alkyl Indeno[1,2‐b]quinoxalin‐11‐ylideneacetates under Solvent‐Free Conditions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

One-Pot Synthesis of Alkyl Indeno[1,2-b]quinoxalin-11-ylideneacetates under Solvent-free Conditions

A series of alkyl indeno[1,2-b]quinoxalin-11-ylideneacetates (3a-f) were prepared using the simple one-pot reactions involving triphenylphosphine, alkyl bromoacetate, ninhydrin, 1,2-phenylenediamines and NaOAc under solvent free-condition.

Asymmetric Synthesis of α- and α,β-Substituted β-Alkoxycarbonyl Sulfonates

An efficient asymmetric synthesis of substituted β-alkoxycarbonyl sulfonates is described. Enantiopure α-substituted β-alkoxycarbonyl sulfonates can be obtained via α-alkylation of metalated sulfonates bearing 1,2:5,6-di-O-isopropylidene-α-d-allofuranose as the chiral auxiliary with alkyl bromoacetates. α,β-Di­substituted β-alkoxycarbonyl sulfonates were prepared starting from the corresponding enantiopure γ-nitro sulfonates by using TFA for the cleavage of the chiral auxiliary and causing a simultaneous Meyer reaction.

Asymmetric Synthesis of β-Substituted γ-Lactams Employing the SAMP-/RAMP-Hydrazone Methodology. Application to the Synthesis of (R)-(-)-Baclofen

A short and efficient asymmetric synthesis of β-substituted γ-lactams is described. Key steps are the α-alkylation of aldehyde SAMP-hydrazones with alkyl bromoacetates, their MMPP mediated conversion to the corresponding nitriles and a reductive cyclization with Raney Ni or Ni boride to the title pyrrolidin-2-ones. The β-substituted γ-lactams are obtained in three steps, good overall yields (27-78%) and excellent enantiomeric excesses (ee = 93-99%). The applicability of this procedure for the asymmetric synthesis of GABAs (y-aminobutyric acids) is demonstrated for (R)-(-)-baclofen hydrochloride, which is obtained in 4 steps, 55% yield and 94% ee.

Preparation and Characterisation of N,N-Disubstituted 2-Amino-5H-selenophenes

Abstract The reaction of N,N’-persubstituted selenoacrylamides with alkyl bromoacetates gives rise to the formation of alkyl derivatives of N,N-disubstituted 2-aminoselenophene-5-carboxylates which can be transformed by saponification into corresponding 5-carboxylic acids. These compounds decompose by heating under formation of hitherto unknown N,N-disubstituted 2-amino-5H-selenophenes their spectral and chemical properties were outlined.

Preparation of New Nitrogen-Bridged Heterocycles. 56. Syntheses and Reactions of 1-[2,2-Bis(alkylthio)-1-(ethoxycarbonylacetyl)vinyl]pyridinium Salts

The title compounds, readily available from the S-alkylation of pyridinium 1-[alkylthio(thiocarbonyl)](ethoxycarbonylacetyl)methylides with alkyl halides or alkyl bromoacetates, were treated with a base and then a dehydrogenating agent to provide some unique products such as 3-[bis(alkylthio)methylene]-2(3H)-indolizinones and dialkyl 7-methyl-4-oxo-1,4,8,8a-tetrahydro-1,4-thiazino[3,4,5-cd]indolizine-1,5-dicarboxylates. On the other hand, similar reaction of these pyridinium salts in the absence of the dehydrogenating agent afforded alkyl 2-hydroxyindlizine-3-carboxythiolates, whose yields were increased by adding trifluoroacetic acid to the reaction mixture. The structures of some products were confirmed by the X-ray analyses.

Efficient and Chemoselective Alkyl Bromoacetate—Zn Mediated Transesterification Method.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Efficient and chemoselective alkyl bromoacetate–Zn mediated transesterification method

Alkyl bromoacetates were shown to be versatile transesterification reagents. Isoxazoles underwent chemoselective transesterification when treated with alkyl bromoacetate–Zn in THF at reflux. A suggested mechanism of the new reaction was discussed.

Dual binding mode of alkylammonium cations to (1,3)-calix[5]crown-6 triesters

Abstract Potentially heteroditopic receptors 1c-h are easily obtained by exhaustive alkylation of (1,3)-calix[5]crown-6 triols 1a ( R ′ = t Bu ) or 1b (R′ = H) with alkyl bromoacetates. 1H NMR titration experiments provide clear evidence for a dual (endo-cavity and/or exo-cavity) binding mode of alkylammonium cations to hosts 1c-h, depending on the shape of the guest and the size of substituents at the upper rim.