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Indanone and its analogues are useful intermediates
1-Indanone and its analogues are useful intermediates for the synthesis of compounds some of which have applications as pharmaceuticals, especially as analgesic and antihypertensive as well as tobacco flavoring agents. Indanones are commonly used as starting agent for the synthesis of ninhydrin which is used determination of fingerprints. Substituted-2,3-dihydrobenzofurans are an important class of biologically active oxygen containing heterocyclic compounds. Natural products possessing the dihydrobenzofuran moiety exhibit a broad range of biological and pharmacological activities . The indeno [5,4-] furan structure is a part of the internal backbone of various important Melatonin MT1/MT2 receptors in the suprachiasmatic nucleus (SCN) for the treatment of circadian rhythm sleep disorders . The invention of relates to certain indenofurans having diuretic-saluretic and antihypertensive pharmacological activity. -Amino alcohol moiety is ubiquitous in nature, the subfamily of -amino cycloalkonols can be found in many natural products and synthetic bioactive molecules, such as the anti-arrhythmic vernakalantor, the inhibitors of HIV (Indinavir) and spleen tyrosine kinase (SYK) . An important -amino alcohol is propranolol, one of the first non-selective -blockers developed, finding wide spread use in the treatment of kasugamycin (). (1,2,3)-Triazole moieties are attractive connecting units because they are stable to metabolic degradation and capable of hydrogen bonding, which can be favorable in the binding of bio-molecular targets and can improve the solubility . These moiety does not occur in nature, although the synthetic molecules that contain (1,2,3)-triazole units show diverse biological activities . In continuation of our research programme , , , , , , to obtain novel bioactive molecules, we synthesized hitherto unreported triazole derivatives of 2-(hydroxymethyl)-7,8-dihydro-1-indeno[5,4-]furan-6(2)-one (). The key intermediate 2-(hydroxymethyl)-7,8-dihydro-1-indeno[5,4-]furan-6(2)-one () () was reacted with Ts-Cl to form its corresponding tosyl derivative, subsequently reacted with sodium azide in DMF at 80 °C for 12 h to afford the 2-(azidomethyl)-7,8-dihydro-1-indeno[5,4-]furan-6(2)-one (). Formation of was confirmed from absorption at 2091 Cm in IR spectrum for the azido function. Next, we synthesized novel 2-((1-1,2,3-triazol-1-yl)methyl)-7,8-dihydro-1-indeno[5,4-]furan-6(2)-one derivatives () click chemistry reaction condition. Thus, 1,3-dipolar cycloaddition reaction of 2-(azidomethyl)-7,8-dihydro-1-indeno[5,4-]furan-6(2)-one () and various terminal acetylene derivatives (), in the presence of catalytic amount of sodium ascorbate and copper sulfate at room temperature, afforded the corresponding 2-((1-1,2,3-triazol-1-yl)methyl)-7,8-dihydro-1-indeno[5,4-]furan-6(2)-one derivatives () () in high yields (85–95%). The structures of these compounds were confirmed from their spectral and micro analytical data. Based on [M+H] 402 its molecular formula of was established as CHON. The IR spectrum of showed absorption due to CO stretching at 1735 Cm & furan ring containing oxygen, stretching at 1045 Cm indicating ether linkage and triazole ring double bond absorption at 1607 Cm. The H NMR spectrum of exhibited signals arising due to typical tertiary carbon proton, multiplet at δ 5.48–5.38 integrating for one proton, triazole containing double bond proton appeared as singlet at δ 8.15. The spectrum also revealed the presence of two dd at δ 4.84 and δ 4.74 (for 2H) due to furan and triazole bridged CH protons. We synthesized novel 5-Hydroxy-2,3-dihydro-1-inden-1-one -amino alcohol derivatives () from 5-hydroxy indanone (). Compound was reacted with (±)-epichlorohydrin under potassium carbonate at 55 °C for 5 h, to achieve the 5-(oxiran-2-ylmethoxy)-2,3-dihydro-1-inden-1-one () in 78% yield. The oxirane of was opened with various substituted piperazines at reflux temperature for 20 h to give 5-Hydroxy-2,3-dihydro-1-inden-1-one -amino alcohol derivatives () in excellent yields ().