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2-(Alkylamino)-3-aryl-6,7-dihydrobenzofuran-4(5H)-ones: Improved Synthesis and their Photophysical Properties.

Kumar M, Kumawat LK, Gupta VK, Sharma A - ChemistryOpen (2015)

Bottom Line: As such, improved synthetic access to furans is an important research goal.This method is significantly improved from previously described protocols in terms of applicability of wide ranging aryl aldehydes, better yields, shorter reaction times, facile work up and essentially no need of column chromatography.Further studies to investigate the UV absorption and luminescence behavior of these compounds revealed their utility as "naked-eye sensors" for aluminum detection.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Indian Institute of Technology Roorkee Roorkee, Uttarakhand, 247667, India.

ABSTRACT
Furans are an important class of compounds and exhibit a diverse range of activities and properties. As such, improved synthetic access to furans is an important research goal. In the present report, a solvent- and catalyst-free reaction between 5,5-dimethyl-1,3-cyclohexanedione (dimedone), an aryl aldehyde and an isocyanide under microwave irradiation is presented. This method is significantly improved from previously described protocols in terms of applicability of wide ranging aryl aldehydes, better yields, shorter reaction times, facile work up and essentially no need of column chromatography. The photophysical properties of this series of compounds were studied for their possible applicability in the field of metal ion sensors. In solution, two compounds, 2-(cyclohexylamino)-3-(1H-indol-3-yl)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-one (1 i) and 2-(tert-butylamino)-3-(1H-indol-3-yl)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-one (1 j), underwent an observable color change from yellow to colorless in the presence of aluminum(III) ions. Further studies to investigate the UV absorption and luminescence behavior of these compounds revealed their utility as "naked-eye sensors" for aluminum detection.

No MeSH data available.


Related in: MedlinePlus

Proposed mechanism for the three-component condensation reaction.
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sch02: Proposed mechanism for the three-component condensation reaction.

Mentions: With optimized conditions in hand, the substrate scope and generality of the protocol was explored, especially with respect to aldehyde input (Table 2). The method seemed to be tolerant to various substituted aryl aldehydes. Specifically, the yields were better in the case of electron-deficient aldehydes (Table 2, entries 2–7 and 11–13). Unfortunately, in the case of 4-methoxy benzaldehyde, the product did not crystallize and remained too impure to be counted (Table 2, entry 8), while reaction of 2,3-dimethoxy aldehyde provided the anticipated product in moderate yield (Table 2, entry 14). This result was expected as the initial enone formed with an electron-rich aryl aldehyde would be less electrophilic and hence less prone to isonitrile attack (Scheme 2). Moreover, the method also tolerated less reactive imidazole-3-carbaldehyde (Table 2, entries 9 and 10). It is noteworthy that 1 a and 1 g were synthesized here with improved yields over those previously reported in the literature.19


2-(Alkylamino)-3-aryl-6,7-dihydrobenzofuran-4(5H)-ones: Improved Synthesis and their Photophysical Properties.

Kumar M, Kumawat LK, Gupta VK, Sharma A - ChemistryOpen (2015)

Proposed mechanism for the three-component condensation reaction.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608531&req=5

sch02: Proposed mechanism for the three-component condensation reaction.
Mentions: With optimized conditions in hand, the substrate scope and generality of the protocol was explored, especially with respect to aldehyde input (Table 2). The method seemed to be tolerant to various substituted aryl aldehydes. Specifically, the yields were better in the case of electron-deficient aldehydes (Table 2, entries 2–7 and 11–13). Unfortunately, in the case of 4-methoxy benzaldehyde, the product did not crystallize and remained too impure to be counted (Table 2, entry 8), while reaction of 2,3-dimethoxy aldehyde provided the anticipated product in moderate yield (Table 2, entry 14). This result was expected as the initial enone formed with an electron-rich aryl aldehyde would be less electrophilic and hence less prone to isonitrile attack (Scheme 2). Moreover, the method also tolerated less reactive imidazole-3-carbaldehyde (Table 2, entries 9 and 10). It is noteworthy that 1 a and 1 g were synthesized here with improved yields over those previously reported in the literature.19

Bottom Line: As such, improved synthetic access to furans is an important research goal.This method is significantly improved from previously described protocols in terms of applicability of wide ranging aryl aldehydes, better yields, shorter reaction times, facile work up and essentially no need of column chromatography.Further studies to investigate the UV absorption and luminescence behavior of these compounds revealed their utility as "naked-eye sensors" for aluminum detection.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Indian Institute of Technology Roorkee Roorkee, Uttarakhand, 247667, India.

ABSTRACT
Furans are an important class of compounds and exhibit a diverse range of activities and properties. As such, improved synthetic access to furans is an important research goal. In the present report, a solvent- and catalyst-free reaction between 5,5-dimethyl-1,3-cyclohexanedione (dimedone), an aryl aldehyde and an isocyanide under microwave irradiation is presented. This method is significantly improved from previously described protocols in terms of applicability of wide ranging aryl aldehydes, better yields, shorter reaction times, facile work up and essentially no need of column chromatography. The photophysical properties of this series of compounds were studied for their possible applicability in the field of metal ion sensors. In solution, two compounds, 2-(cyclohexylamino)-3-(1H-indol-3-yl)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-one (1 i) and 2-(tert-butylamino)-3-(1H-indol-3-yl)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-one (1 j), underwent an observable color change from yellow to colorless in the presence of aluminum(III) ions. Further studies to investigate the UV absorption and luminescence behavior of these compounds revealed their utility as "naked-eye sensors" for aluminum detection.

No MeSH data available.


Related in: MedlinePlus