Synthesis of New Planar-Chiral Linked [2.2]Paracyclophanes-
N-([2.2]-Paracyclophanylcarbamoyl)-4-([2.2]Paracyclophanylcarboxamide, [2.2]Paracyclophanyl-Substituted Triazolthiones and -Substituted Oxadiazoles.
Molecules 2020;
25:molecules25153315. [PMID:
32707754 PMCID:
PMC7436044 DOI:
10.3390/molecules25153315]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 01/26/2023] Open
Abstract
The manuscript describes the synthesis of new racemic and chiral linked paracyclophane assigned as N-5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carbamoyl)-5’-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carboxamide. The procedure depends upon the reaction of 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)hydrazide with 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)isocyanate. To prepare the homochiral linked paracyclophane of a compound, the enantioselectivity of 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carbaldehyde (enantiomeric purity 60% ee), was oxidized to the corresponding acid, which on chlorination, gave the corresponding acid chloride of [2.2]paracyclophane. Following up on the same procedure applied for the preparation of racemic-carbamoyl and purified by HPLC purification, we succeeded to obtain the target Sp-Sp-N-5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carbamoyl)-5’-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carboxamide. Subjecting N-5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)hydrazide to various isothiocyanates, the corresponding paracyclophanyl-acylthiosemicarbazides were obtained. The latter compounds were then cyclized to a new series of 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)-2,4-dihydro-3H-1,2,4-triazol-3-thiones. 5-(1,4(1,4)-Dibenzenacyclohexaphane-12-yl)-1,3,4-oxadiazol-2-amines were also synthesized in good yields via internal cyclization of the same paracyclophanyl-acylthiosemicarbazides. NMR, IR, and mass spectra (HRMS) were used to elucidate the structure of the obtained products. The X-ray structure analysis was also used as an unambiguous tool to elucidate the structure of the products.
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