Reimer-Tiemann Reaction Research Articles

A simple spectrophotometric method for chloroform quantification and its application in chloroform degradation from laboratory wastewater using polyphenolic co-activators

A simple spectrophotometric method for measuring high concentration of chloroform in water was developed based on the Reimer-Tiemann reaction. The reaction between chloroform and resorcinol under alkaline conditions has the limit of detection (LOD) and limit of quantification (LOQ) values at 1.28 mg/mL and 3.88 mg/mL, respectively. The experimental and response surface methodology (RSM) proposed the optimal conditions for the removal of chloroform (RoC) using tannic acid as a polyphenolic co-activator and spectrophotometric method for chloroform detection. The acceptable dechlorination process was suggested as persulfate (0.1–0.11 M), NaOH (0.6–0.8 M), and tannic acid (1.8 g/L) to obtain the yield of RoC from 76.14 to 77.90%. In situ experiments were then designed for RoC from the laboratory’s aqueous and organic solvent waste. After being treated with the system mentioned above, the yields of RoC were around 70%. In addition, a critical aspect of the innovation process was replacing pure tannic acid with other natural agents, which are more economically efficient and eco-safety. The EtOH extract from Elaeocarpus hygrophilus leaves (EEL) was suggested as a natural source of polyphenols, which could co-activate persulfate, with the yield of RoC rising to 63.29%. The findings of this study provide a novel strategy for chloroform degradation from laboratory wastewater using polyphenols.

Total Synthesis of Neuroprotective Agents, (+)-Lycibarbarine A and (-)-Lycibarbarine B.

We describe the convergent total syntheses of lycibarbarines A and B which are potent neuroprotective agents recently isolated from the fruits of Lycium barbarum. The synthesis highlights the construction of a unique spiro oxazine heterocyclic motif imbedded in these natural products. The synthesis is accomplished from the commercially available 8-hydroxyquinaline and 2-deoxy-d-ribose as key starting materials. The synthesis features a Reimer-Tiemann reaction, selective amine alkylation with a keto tosylate derivative, and spiroketalization to form an oxazine core.

Capturing Reactive Carbanions by Microdroplets.

Carbanions appear in many organic or biological reactions as fleeting intermediates, prohibiting direct observation or spectroscopic measurement. An aqueous environment is known to rapidly annihilate a carbanion species, reducing its lifetime to as short as picoseconds. We report that aqueous microdroplets can capture and stabilize reactive carbanion intermediates isolated from four classic organic reactions, aldol and Knoevenagel condensations, alkyne alkylation, and the Reimer-Tiemann reaction, enabling the detection of their carbanion intermediates by desorption electrospray ionization mass spectrometry. This is accomplished in real time of the reaction, allowing new insights into reaction mechanisms to be obtained. The efficacy of microdroplets in capturing such elusive species was examined by varying the solvent and the microdroplet negative charge density. We observed that microdroplets composed of water-methanol outperform other solvents, such as pure water, in capturing carbanions, which is in contrast to the earlier report that presented the highest performance of pure water microdroplets in capturing carbocations. We offer some mechanistic insights to explain the discriminatory behavior of these two oppositely charged species in microdroplets.

A Comprehensive Experiment on Synthesis of Aggregation-Induced Emitting Salicylaldehyde Azine Using Reimer-Tiemann Reaction

A Comprehensive Experiment on Synthesis of Aggregation-Induced Emitting Salicylaldehyde Azine Using Reimer-Tiemann Reaction

Synthesis and antibacterial activity test of 3-(3-(4-hydroxy-3-methylphenyl)akriloil) coumarin compounds

A 3-(3-(4-hydroxy-3-methylphenyl)acryloyl) coumarin has been synthesized from 4-hydroxy-3-methylbenzaldehyde with 3-acetylcoumarin. This research includes the synthesis of 4-hydroxy-3-metilbenzaldehid from ortho-cresol through Reimer-Tiemann reaction, synthesis of 3-acetylcoumarin from salicylaldehyde, synthesis of 3-(3-(4-hydroxy-3-methylphenyl)acryloyl)coumarin, and antibacterial activity testing of 3-(3-(4-hydroxy-3-methylphenyl)acryloyl)coumarin compound against Escherichia coli (gram negative bacteria) and Staphylococcus aureus (gram positive bacteria) using the disc diffusion method. The result of Reimer-Tiemann reaction was obtained as a yellow solid of 4-hydroxy-3-methylbenzaldehyde with yield of 31.91%. The synthesis of 3-acetylcoumarin was obtained as a yellow solid with a yield of 95.57%. A 3-(3-(4-hydroxy-3-methylphenyl)acryloyl)coumarin was obtained as a brownish yellow solids with yield of 11.66%. A 3-(3-(4-hydroxy-3-methylphenyl)acryloyl) coumarin has better antibacterial activity than 3-acetylcoumarin compound against Escherichia coli and Staphylococcus aureus.

Palladium-catalyzed C-H formylation of electron-rich heteroarenes through radical dichloromethylation

A novel palladium-catalyzed C-H formylation of electron-rich N-, O-, and S-containing heteroarenes has been developed. The key to success is that the commercially available BrCHCl2 was used as a stoichiometric carbonyl source. Mechanistic investigations indicated that different from the known Reimer-Tiemann reaction, this net C-H formylation proceeded through an electrophilc radical-type path.

Synthesis of 4-hydroxy-3-methylchalcone from Reimer-Tiemann reaction product and its antibacterial activity test

A 4-hydroxy-3-methylchalcone has been synthesized from 4-hydroxy-3-methylbenzaldehyde as the Reimer-Tiemann reaction product. This research consists of three steps involve synthesize of 4-hydroxy-3-methylbenzaldehyde from ortho-cresol, synthesize of chalcone derivatives from 4-hydroxy-3-methylbenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde or vanillin for the comparison, the last is antibacterial activity test of both chalcone derivatives against Escherichia coli (negative gram) and Staphylococcus aureus (positive gram) bacteria using disc diffusion method. Results of Reimer-Tiemann reaction is 4-hydroxy-3-methylbenzaldehyde compound in an orange colour solid form which has 43% yields and melting point 110-114°C. A 4-hydroxy-3-methylbenzaldehyde then reacted with acetophenone in a base condition and form 4-hydroxy-3-methylchalcone compound in a yellow colour solid form which has 40% yields and melting point 83-86°C. The antibacterial activity of the 4-hydroxy-3-methylchalcone against gram-positive bacteria Staphylococcus aureus is better than the 4-hydroxy-3-methoxychalcone.

Zeolites as Shape-Selective Catalysts: Highly Selective Synthesis of Vanillin from Reimer–Tiemann Reaction of Guaiacol and Chloroform

Reimer–Tiemann reaction of guaiacol and chloroform was carried out in the presence of various zeolites. Vanillin was afforded as major product in a high selectivity. Zeolites played an important role of shape-selective catalysts in the reactions. Among the examined zeolites, ZSM-5 showed the best result to give the desired product vanillin in 85 % selectivity and 58 % yield.

Derivatization of Coumarins at the Benzenoid Ring in Aqueous Medium

Some 6‐disubstituted, 8‐disubstituted, and/6,8‐disubstituted compounds have been prepared from coumarin, 7‐methylcoumarin, and 3,4‐benzocoumarin. The Reimer–Tiemann reaction, Lederer–Manasse reaction, bromination using molecular bromine as well as 2,4,4,6‐tetrabromocyclohex‐2,5‐dien‐1‐one, Elbs reaction, and diazocoupling have been carried under controlled conditions to obtain various derivatives. Further, several reactions of aldehyde derivatives of these coumarins have been carried on to prepare important functional compounds including some heterocycles. It is noteworthy that these aldehydes behave as phenolic aldehydes under alkaline conditions to undergo the Dakin reaction. The reactions are mostly carried in aqueous media involving a dianionic intermediate and hence fulfill one important criterion of green chemistry.

Organometallic Sn(II) catalyzing adducts of substituted benzaldehydes

This paper reports about the electrospray ionization mass spectrometric and quantum chemical study of unique coupling reaction of dihydroxybenzaldehydes in strong basic medium, which in the presence of SnIVCl4 yielded series of condensation products through the homo Dies-Alder reaction of the bicyclohexyl-4,6,4′,6′-tetraene-2,3,2′,3′-tetraone (2). In contrast to the known coupling reaction products catalyzing by diversity of CuI/CuII-, AgI-, Au0/AuIII/AuI-, ZnII-, Pd0/PdIII/PdII- and/or PtII-organometallics, yielding the substituted biphenyls, benzo-[c]-cromenes, condensation products of 5,6,11,12-tetraoxo-tricyclo[6.2.2.02,7]dodeca-3,9-diene-1,4-dicarbaldehyde (14) type from 2,3-dihydroxybenzaldehyde particularly, and/or substituted aldehydes by Reimer–Tiemann reaction, in the presence of SnIVCl4, the formation of above dimeric adducts is chiefly process, explained with SnIV→SnII redox process. The known product 14 is obtained at trace concentrations, producing further dimeric 5,6,11,12,5′,6′,11′,12′-octaoxo-[4,4′]bi[tricyclo[6.2.2.02,7]dodecyl]-3,9,3′,9′-tetraene-1,1′-dicarbaldehyde adduct (15). The catalyzing organometallic precursor is a binuclear SnII-complex (I), where the metal ion is bonded covalently in ClSnC manner. A second metal ion is bidentately coordinated to adjacent OC groups, forming a five membered chelate ring. The Cl− and OH−-terminal ligands completed the SnO3Cl chromophore. The experimentally evidenced complex I exhibited a significant thermodynamics stability of ΔG=−52996.80kcalmol−1, a value different than Δ(ΔG)=|52945| kcalmol−1 towards the corresponding quantities of other structurally proposed analogous of SnII, SnIV or SnII/SnIV organometallics II–IV on the base of the MS elemental compositions and isotopic shapes.

ChemInform Abstract: Reimer—Tiemann Reaction of Coumarins.

AbstractImproved yields of aldehydes (III) are achieved when the Reimer—Tiemann reaction is carried out as a 2‐step process.

Synthesis and Antifungal Activities of Some Aryl Naphthofuran Ketoximes

In this study, some aryl naphtho[2,1-b]furan-2-yl ketoximes and their ethers and esters were synthesised. The structure elucidation of the compounds was performed by IR, 1H-NMR and MASS spectroscopic data and elemental analyses results. Antifungal activities of the compounds were tested against Candida albicans (two strains), Candida glabrata, Candida tropicalis and Candida parapsilosis using a microbroth dilution technique. The results showed that the compounds displayed minimum inhibitory concentrations, 7.8-625 µ g/mL. Keywords: Aryl naphthofuran ketoximes, Aryl naphthofuran O-methylketoximes, Aryl naphthofuran ketoxime acetates, Antifungal activity, Antifungal activities, Candida albicans, Candida glabrata, naphtho[2,1-b]furan-2-yl ketoximes, azole, oxime, diaryl ketoximes, benzofuran-2-yl ketoxime, tetramethylsilane (TMS), Reimer-Tiemann reaction procedure

Reimer–Tiemann Reaction of Coumarins

Improved yields of aldehydes from the Reimer–Tiemann reaction of coumarin and two of its derivatives, namely 7-methylcoumarin and 3,4-benzocoumarin, are obtained by carrying the reaction in a two-step procedure. Using crown ether as phase transfer catalyst, a further improvement in the yield of products is achieved. Additionally, coumarin and 7-methylcoumarin are shown to give dialdehydes under this condition. Dialdehydes are reported for the first time from the Reimer–Tiemann reaction.

Regioselective ortho-formylation of hydroxy-substituted spironaphthooxazine

Formylation of photochromic 9′-hydroxy-1,3,3-trimethyl-1,3-dihydrospiro[2H-indole-2,3′-3′H-naphtho[2,1-b][1,4]oxazine] with the paraformaldehyde-MgCl2-Et3N system or by the Reimer-Tiemann reaction proceeds at the ortho-position to the hydroxy group to form 10′-formyl derivative.

A significant role of alkaline cations on the Reimer–Tiemann reaction

The Reimer-Tiemann (R-T) reaction was investigated by DFT calculations. A model composed of CHCl(3), PhO(-)(Na(+))H(2)O and [NaOH(H(2)O)(2)](2) was employed for geometry optimizations. A K(+)-containing model was also investigated. The dichlorocarbene reagent, which has been thought of for a long time, was found to intervene only transiently in the carbenoid form. In this form, the Na(+) (or K(+)) coordination to CCl(2) enhances its electrophilicity toward C(6)H(5)O(-). The counter ion also works to stabilize the precursor phenoxide ion and intermediates of the substituted phenoxides in the hexagonal pyramidal coordination. The Na(+)-containing reaction consists of seven elementary processes, (K(+), six ones) with extremely high exothermicity and spontaneity.

SEMI-SINTESIS VANILI DARI GUAIAKOL VIA REAKSI REIMERTIEMANN YANG DIKATALISIS DENGAN KATALIS TRANSFER FASE/PTC: [18]-CROWN ETHER-6

Reimer-Tiemann reaction belongs to the group of the electrophylic substitution reaction (SE), and principally, this reaction consists of three steps reactions, namely: 1. formation of dichlorocarbene from chloroform by action of base(i.e. KOH),  2. reaction of dichlorocarbene as electrophyl to the benzene (or general aromatic) nucleus, 3. hydrolysis of the formed dichloromethyl benzene to the derivative of benzaldehyde. In this work has been carried out the modification of Reimer-Tiemann reaction with the goal to synthesize vanillin from guaiacol (o-methoxyphenol) as well as to compare with the conventional Reimer-Tiemann reaction. By the way, the modification of Reimer-Tiemann by using phase transfer catalyst and ethanol as co-solvent can obviously enhance the yield of vanillin up to 51.2% compared with the yield of conventional Reimer-Tiemann to synthesize of vanillin (up to 24.4%). Key words: Reimer-Tiemann reaction, guaiacol, chloroform, vanillin

ChemInform Abstract: Anomalous Reimer-Tiemann Reaction from Phenol, Chloroform, and Potassium Fluoride in Sulfolane.

Abstract Phenol reacts only at the oxygen site when opposed to chloroform in the presence of potassium fluoride and sulfolane. (Difluoromethoxy) benzene and phenyl ortho- formate are formed. This leads to questions about the mechanism of the Reimer-Tiemann reaction.

α-Glucosidase inhibitory antihyperglycemic activity of substituted chromenone derivatives

Series of 3,4- and 3,6-disubstituted chromenones including new chromenone derivatives were synthesized applying various synthetic strategies including Pechmann condensation, Knoevenagel condensation, Reimer–Tiemann reaction and Suzuki coupling in very good yields. Synthesized compounds ( 4a– z) were screened for in vitro α-glucosidase inhibitory and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities. Majority of compounds displayed varying degrees of α-glucosidase inhibitory and DPPH scavenging activity. Compound 4x emerged as the most potent α-glucosidase inhibitor in present series of compounds owing to the presence of 3-acetyl-6-(6-methoxy-3-pyridyl) group on chromenone; however, it could not display DPPH scavenging activity and was found to be mixed non-competitive type inhibitor of rat intestinal α-glucosidase. When tested in vivo for antihyperglycemic activity in starch loaded Wistar rats, it displayed significant antihyperglycemic property. This is the first report assigning rat intestinal α-glucosidase inhibitory property for this class of new chromenones and presents new family of compounds possessing α-glucosidase inhibitory activities and antihyperglycemic property. Compound 4x may serve as an interesting new compound for the development of therapeutics targeted against diet-induced hyperglycemia in diabetes.

Synthesis of Substituted 2‐Hydroxyaryl Aldehydes by the Microwave‐Induced Reimer—Tiemann Reaction.

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, please click on HTML or PDF.

Synthesis of substituted 2-hydroxyaryl aldehydes by the microwave-induced Reimer-Tiemann reaction

Synthesis of substituted 2-hydroxyaryl aldehydes by the microwave-induced Reimer-Tiemann reaction