Reactions of squaric acid and some derivatives with thionyl chloride/,-dimethylformamide

Selms, Roy C. De; Fox, Charles; Riordan, Raymond

doi:10.1016/s0040-4039(01)97828-1

Cited by 48 publications

(18 citation statements)

References 2 publications

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“…The N,N-diethylaniline-based semi-squaraine (compound 1) and N,N-bis(2-(ethylthio)ethyl) aniline (compound 2) were synthesised according to the literature procedures (27,28). SQ2 was then obtained by the condensation of compounds 1 and 2 in toluene/n-butanol (1:1, v/v) under reflux, and characterised by 1 H, 13 C NMR and high-resolution MS.…”

Section: Resultsmentioning

confidence: 99%

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Supramolecular assembly of a new squaraine and β-cyclodextrin for detection of thiol-containing amino acids in water

Luo

Zhou

Lei

et al. 2011

Supramolecular Chemistry

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2011) Supramolecular assembly of a new squaraine and β-cyclodextrin for detection of thiol-containing amino acids in water, Supramolecular Chemistry, 23:9, 657-662, A new unsymmetrical aniline-based squaraine (SQ2) bearing binding unit of Hg 2þ ion was designed and synthesised. SQ2 can form 1:2 inclusion complex with b-cyclodextrin, and the resulting complex, which undergoes absorption and fluorescence bleaching upon binding Hg 2þ , can serve as a turn-on colorimetric or fluorescent chemosensor in organic solvent-free aqueous solution for thiol-containing amino acids with high selectivity and tunable measuring range.

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Section: Resultsmentioning

confidence: 99%

“…Compounds 1 and 2 (Scheme 1) were synthesised according to the reported literatures (27,28). SQ2 was then synthesised by the condensation of compounds 1 and 2 with azeotropic removal of water in n-butanol/toluene …”

Section: Synthesis Of Sq2mentioning

confidence: 99%

Supramolecular assembly of a new squaraine and β-cyclodextrin for detection of thiol-containing amino acids in water

Luo

Zhou

Lei

et al. 2011

Supramolecular Chemistry

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“…The synthetic yields for the acid dichloride and the diethyl ester were reported to be 42-75% (21,22) and 77% (23), respectively, from squaric acid. Assuming that both hydrolysis reactions in Scheme 1 are quantitative, the overall yield of 4 (from squaric acid) would be in the range of 8.5-24%, due to the low yields obtained in the Friedel-Crafts reaction (33%) and the arylation reaction (1 1%).…”

Section: Resultsmentioning

confidence: 99%

Squaraine chemistry. A new approach to symmetrical and unsymmetrical photoconductive squaraines. Characterization and solid state properties of these materials

Law¹,

Bailey²

1993

Can. J. Chem.

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A new approach to l-(p-dimethylaminophenyl)-2-hydroxycyclobutene-3,4-dione (4), a precursor for the synthesis of symmetrical and unsymmetrical photoconductive squaraines, is described. In situ generation of p-nitrophenyl ketene, by the reaction of p-nitrophenylacetyl chloride and triethylamine in the presence of tetraethoxyethylene in anhydrous ether, results in a (2+2) cycloaddition between the ketene and the electron-rich olefin. The cycloadduct generated, 6, was hydrolyzed to give 1-(p-nitropheny1)-2-hydroxycyclobutene-3,4-dione (5) in 51% yield. Reductive alkylation of 5 by hydrogen in the presence of formaldehyde in DMF at 50-60°C affords 4 in 81 % yield. The overall yield of 4 is 41 % from tetraethoxyethylene and is significantly better than other preparative procedures of 4 based on a partial Friedel-Crafts reaction or an arylation reaction of a squaric acid derivative with an aniline, where yields ranging from 8.5% to 24% were reported. Condensations of 4 with 2 equivalents of N, N-dimethylaniline and its derivatives in refluxing 2-propan01 in the presence of 6 equivalents of tributyl orthoformate yield symmetrical squaraine l a and unsymmetrical squaraines lb-le. The synthesis is accomplished by a (2+2) cycloaddition -reductive alkylation -condensation reaction sequence and represents a new, cost-effective synthesis for photoconductive squaraines where the expensive squaric acid reactant is bypassed. The spectroscopic and the solid state properties of la-le have been studied. Results show that the properties exhibited by l a -l e are essentially identical to those exhibited by other photoconductive, symmetrical squaraines that are synthesized by other known processes. From the resemblance in solid state properties, la-le are expected to be photoconductive. This has indeed been observed in preliminary experiments.KOCK-YEE LAW et F. COURT BAILEY. Can. J. Chem. 71,494 (1993) On dCcrit une nouvelle approche pour la preparation de la l-(p-dimethylaminophCnyl)-2-hydroxycyclobut~ne-3,4-dione (4), un precurseur dans la synthese de squarai'nes photoconductrices symetriques et non-symetriques. La generation in situ du p-nitrophknyl cetene, par la reaction du chlorure de p-nitrophCnylacetyle avec la triethylamine en presence de tCtraCthoxy6thylene dans l'ether anhydre, conduit 2 une cycloaddition (2+2) du c$t&ne et de l'olefine riche en electrons. L'hydrolyse du cycloadduit, 6, ainsi gCnerC conduit 2 la 1-(p-nitrophCny1)-2-hydroxycyclobut&ne-3-done (5) avec un rendement de 51%. L'alkylation reductrice de 5 par de l'hydrogene en presence de formaldehyde dans de DMF, a 50-60°C, fournit le composC 4 avec un rendement de 8 1 %. Le rendement global de 4 est de 41% B p a i r du tCtrakthoxy6thylene et ce rendement est supkrieur a ceux obtenus lors de preparations impliquant une reaction de Friedel-Crafts partielle ou une reaction d'arylation d'un derive de l'acide squarique avec de l'aniline alors que les rendements rapportks sont de l'ordre de 8,5 a 24%. Les condensations de 4 avec deux equivalents de N,N-dimethylanil...

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“…Squaryl dichloride (mp 44-46°C) was prepared in 46% yield by the reaction squaric acid and thionyl chloride according to the procedure reported by De Selms et al [13] and purified by recrystallization from hexane. PEO (Aldrich Co., M n =6.0×10 5 ), squaric acid, triethylamine, hydroquinone, thionyl chloride, chloromethylsilane were used as received.…”

Section: Methodsmentioning

confidence: 99%

Solid polymer electrolytes based on squaric acid structure

Itoh

Hirai

Uno

et al. 2007

Ionics

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Poly(squarate)s (PPS-1 and PPS-2) were synthesized by the reaction of squaryl dichloride with hydroquinone for PPS-1 and with 2,5-diethoxy-1,4-bis(trimethylsilyloxy) benzene for PPS-2, and the ionic conductivities, thermal properties, and electrochemical and thermal properties of their polymer electrolytes with LiN(CF 3 SO 2 ) 2 were investigated. The ionic conductivity increased with increasing the lithium salt concentration for the PPS-1-LiN(CF 3 SO 2 ) 2 electrolyte, and the highest ionic conductivities of 8.60× 10 −5 S/cm at 100°C and 9.57×10 −8 S/cm at 30°C were found at the [Li] to [O] ratio of 2:1. And also, the ionic conductivity for the PPS-1-LiN(CF 3 SO 2 ) 2 electrolyte increased with an increase in the lithium salt concentration, reached a maximum value at the [Li] to [O] ratio of 1:2, and then decreased. The highest ionic conductivity was to be 1.04×10 −5 S/cm at 100°C and 1.71×10 −8 S/cm at 30°C, respectively. Both polymer electrolytes exhibited relatively better electrochemical and thermal stabilities. Addition of the PPS-1 as a plasticizer into the poly(ethylene oxide) (PEO)-LiN(CF 3 SO 2 ) 2 electrolyte system suppressed the crystallization of PEO, and improved the ionic conductivity at room temperature.

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Reactions of squaric acid and some derivatives with thionyl chloride/,-dimethylformamide

Cited by 48 publications

References 2 publications

Supramolecular assembly of a new squaraine and β-cyclodextrin for detection of thiol-containing amino acids in water

Supramolecular assembly of a new squaraine and β-cyclodextrin for detection of thiol-containing amino acids in water

Squaraine chemistry. A new approach to symmetrical and unsymmetrical photoconductive squaraines. Characterization and solid state properties of these materials

Solid polymer electrolytes based on squaric acid structure

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