11- 4,5,6-Trimethoxynicotinonitrile-2-thion (39) was prepared through the multicomponent, condensation of acetaldehyde, cyanothio acetamide, 1-(butenyl)pyrrolidine. Compound (39) reacted with some alkyl halides yielding 2-alkylsulfanyl nicotinonitriles (40)106, scheme 41. 12- The one‐pot multicomponent condensation of malononitrile, 4‐methyl-pentan‐2‐one, aryl aldehyde, and ammonium acetate in ethanol yielded the 2‐amino‐5‐isopropyl‐4‐(4‐aryl)‐6‐methyl nicotinonitriles (41 a-f), which exhibited weak antioxidant activity107, scheme 42. 1.3.3. Catalysis mediated Synthesis of nicotinonitriles 1- The ammoxidation of 3-picoline to 3-nicotinonitrile (42) was induced by the influence of industrially synthesized and shaped vanadium phosphate …show more content…
5- When CuCl2 was used as a catalyst, the desired 2-aminonicotino-nitrile products (47) were obtained as a result of multicomponent reaction of O-pivaloylacetophenone oxime, benzaldehyde, and malonitrile in different solvents and different yield112, scheme 47. 6- The four component condensation of acetophenone, arylaldehydes, arylthiol, and malononitrile in the presence of non-ionic surfactants (Triton X-100, 5 mol%) afforded new derivatives of 4,6-diaryl-2-(arylthio)nicotinonitriles (48) in (80-95%) yield113, scheme 48. 7- Tetrabutyl ammonium bromide was used as catalyze in aqueous medium for efficient synthesis of a new series of 2-amino-nicotinonitriles (49), through the one-pot multi-component reaction strategy with overall yield (72-93%)114, scheme 49. 1.3.5. Microwave assisted synthesis approach for …show more content…
L. Zhu et. al., reported the synthesis of new derivatives of 4-aryl-3,5-dicyano-2,6-di(3′-indolyl)pyridine (50) and polysubstituted (3′-indolyl)pyrazolo[3,4-b]pyridine and (3′-indolyl)benzo[h]quinolines (51) via a one-pot multicomponent reaction of aromatic aldehydes, 3-cyanoacetyl indoles, and ammonium acetate employing the microwave irradiation as an energy source and ethylene glycol as a solvent,115,116 scheme 50. 2- A series of 4-aryl-6-(indol-3-yl)-2,2-bipyridine-5-carbonitrile derivatives (52) were synthesized within shorter reaction time and high product yield via a one-pot multicomponent reaction of aromatic aldehydes, 3-(cyanoacetyl)indole, and 2-acetyl pyridine in ammonium acetate by microwave irradiation in solvent-free condition. The same conditions were applied for the synthesis of anther series of di(indol-3-yl)-diaryl bipyridine-dicarbonitrile derivatives (53a-e) using cinnamils, 3-cyanoacetyl indole and ammonium acetate117, scheme
Furthermore, the principles and metrics of green chemistry were incorporated into the synthesis reaction through the use of the benign solvent, water. Through the use of the vacuum filtration and the recrystallization procedures, the product was further purified. Subsequently, the purity and identity of the product were evaluated through the analysis tool of Nuclear Magnetic Resonance. Ultimately, the efficiency and greenness of the reaction were measured through the calculation of the percent yield and the atom
Using SN1 reaction mechanism with hydrochloric acid, t-Pentyl alcohol was converted to t-Pentyl chloride in an acid catalyzed reaction. The reaction took place in a separatory funnel designed to separate immiscible liquids. The crude product was extracted by transferring a solute from one solvent to another. The process of washing the solutions by phase transfer was used in order to remove impurities from the main solvent layer. Finally, the crude product was dried with anhydrous Calcium chloride and purified once more by simple distillation technique.
1. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene.
Protocols for synthesising 1,3-butadienes from aldehydes and ketones have been established in the literature. The synthesis protocol identified by Greatrex et al. (2014) was
The solid residue was filtered and filtrate washed with chloroform three times. Filtrate was dried over anhydrous Na2SO4 and solvent was distilled off leaving pure white solid crude compound (2) (about 90 % yield). 2. Synthesis of 3-Prop-2-ynyl-pentane-2,4-dione (Scheme-2) Acetylacetone (2, 4-pentadione) is an active methylene compound that exists in keto-enol forms in equilibrium.
2-Mercaptobenzothiazole (Fig. 1) was first obtained by A. W. Hofmann by the reaction of carbon disulfide and o-aminophenol in 1887. He also obtained the same product by the action of sodium hydro-sulfide on chlorophenyl mustard oil (1-chlorobenzothiazole). 2-Mercaptobenzothiazole was recrystallized from alcohol and melting point was found to be 179 oC. The product was easily oxidized to a disulfide derivative (M.P. 180 oC). Further, Hofmann noted formation of 2-anilinobenzothiazole from the reaction of 2-aminothiophenol and phenyl isothiocyanate.45
8-hydroxyquinoline (8-HQ) is a bicyclic compound derived from quinoline (1-azanaphthalene) and consist of two rings system: carbocyclic ring and pyridine ring with hydroxyl group substituted at position-8. 8-HQ is one of the most popular and versatile organic compound is an organic crystalline material. 8-HQ has typical phenolic properties, e.g. it gives violet colour with ferric chloride, couple with diazonium cations, and participate in Reimer-Tiemann and Bucherer reactions; its acetate ester usually undergoes the Fries rearrangement with aluminium chloride to give acetyl derivative [1]. As a result of the proximity of the hydroxyl group to the heterocyclic nitrogen, 8-HQ forms insoluble chelate complexes with a great variety of metal ions, including Cu2+, Bi2+, Mn2+, Mg2+, Fe3+, Al3+, Zn2+and Ni3+ [3]. The hydrogen of the hydroxyl group in 8-HQ is displaced and the metal is linked to both the oxygen and nitrogen.
The IR spectrum of 8a showed stretching bands for the N−H bond at 3357 cm–1 and for C=O bonds of the lactone and ester functionalities at 1733, 1677 and 1614 cm–1. The mass spectrum of 8a displayed the molecular ion (M+) peak at m/z = 425, which was 16 units (an oxygen atom) less than that of the 1:1:1:1 adduct of salicylaldehyde, Meldrum’s acid, cyclohexyl isocyanide and dimethyl acetylenedicarboxylate with the loss of a H2O and an acetone molecule. The 1H-NMR spectrum of 8a exhibited three single sharp lines arising from the two methoxy groups (at δ(H) 3.78 and 3.94 ppm) and the coumarin vinylic H atom (at 7.77). A fairly sharp doublet was seen at 6.83 (J = 8.2 Hz) for the amine NH group because of coupling with the CH of the cyclohexyl ring. Characteristic multiplets with appropriate chemical shifts and coupling constants for the eleven H-atoms of the cyclohexyl ring and the four H-atoms of the aromatic moiety were observed in the aliphatic and aromatic region of the spectrum, respectively. The 1H-decoupled 13C-NMR spectrum of 8a showed characteristic signals at δ(C) 24.5, 25.4 and 33.4 ppm (due to the methylenes of the cyclohexyl ring), 51.3 and 52.5 (for the two methoxy groups), and 51.5 (arising from the NCH moiety). A shielded resonance was observed at 88.8 (due to the NOC=C moiety) as well as five deshielded resonances
Costin T. A. et al., (2017) designed a series to show the reactivity of a diazobketo esters with primary amines of linear structure, it was reported that n-butylamine and allylamine are potent nucleophiles for the acyl cleavage of a-diazo-b-keto esters having electron withdrawing groups at respective position, such as azido and chloro , giving to the corresponding amides (71) in high
One-pot synthesis of substituted pyrroles 6.8 by a cascade reaction of azides with Morita–Baylis–Hillman acetates of acetylenic aldehydes 6.9 was described and the reaction was efficiently mediated by triphenylphosphine at room temperature (scheme 6.4). Sodium azide was successfully used to provide N-unsubstituted pyrroles, while alkyl azides afforded the corresponding N-alkylated pyrroles through a sequence of allylic substitution/azide reduction/cycloisomerization reactions. The obtained products have provided a new entry to indolizino indoles, pyrrolo isoquinolines and 8-oxo-5,6,7,8-tetrahydroindolizine.30
Symmetrical calix[n]arenes with specific number of identically substituted phenol rings can be prepared in one step from the base-catalyzed condensation of a phenol and formaldehyde (Figure U) (Lang, J., Vlach, J., Dvořáková, H., Lhoták, P., Himl, M., Hrabal, R., & Stibor, I. ,2001). As the synthesis comprise of only one step, so the yields
Protocols for synthesising 1,3-butadienes from aldehydes and ketones have been established in the literature. The synthesis protocol proposed by Greatrex et al. (2014) was used and reactions using several aldehydes (cinnamaldehyde, piperonaldehyde, and 2-chloro-benzaldehyde) were successfully performed to synthesise the required butadienes 1, 2, and 3, Scheme 2.
The mechanism for the step-by-step synthesis of B-citronellyl tosylate from B-citronellol is described in Scheme 1 and Scheme 2, including side products formed. The first step involves performing the reduction of B-citronellal in the solvent methanol and using NaBH4 as a source of hydride ions to reduce an aldehyde to form an alkoxide ion, later protonated by adding dilute HCl.1 This is followed by neutralizing the reaction mixture with NaHCO3, and extraction of crude B-citronellol from the organic layer (DCM). The intermediate compound was a clear liquid after allowing a week to evaporate off as much excess solvent as possible. The experimental yield was 1.04g.
Abstract A series of new 4-(1-azidoethyl)-1,1 '-biphenyl derivatives were synthesized by the metal-free reductive reactions of biphenyl tosylhydrazones and sodium azide. The resulting biphenyl derivatives were further reacted with aryl acetylenes to afford novel 1,4-substituted 1,2,3-triazoles in 41–94% yield by water-soluble salen-Cu(II) catalyzed azide–alkyne cycloaddition in water in the absence of any organic solvent or phase transfer agent. Moreover, the catalytic system exhibited wide substrate scope and high functional-group tolerances.
As a consequence of their importance in many research fields, there is a growing interest on the synthesis of indolizine derivatives. Although many synthetic methods are available in the literature, (Li and Chua, 2011, Kostik et al, 2001) a frequently employed approach is the 1, 3-dipolar cycloaddition of