5,6,7,8-Tetrahydronaphthalen-1-amine as Precursor for Thiazolidi­nones and Benzothiazepinones: Synthesis and Atropisomeric Relationship

Abstract

The one-pot reaction of 5,6,7,8-tetrahydronaphthalen-1-amine, mercaptoacetic acid, and arenealdehydes having strong and weak electron-withdrawing groups gave the corresponding 1,3-thiazolidin-4-ones (47–70%). When arenealdehydes bearing strong and weak electron-donating groups were used as precursors, the 1,4-benzothiazepin-2-ones were obtained (30–72%) by p-TsOH catalysis. All compounds are unknown and were characterized by GC-MS and NMR techniques, and available crystals by X-ray diffraction studies. The atropisomerism phenomenon was observed in several 1,3-thiazolidin-4-ones as confirmed by VTNMR method. The Tc was established as 332 K and the energy required for the interconversion of one atrop­isomer into another is around 16.8 kcal·mol–1. Chemical quantum calculation and NOESY displayed that more stable isomer has the tetrahydro­naphthalene portion below the five-ring plane. Only a small difference between isomers (–0.21 to –0.84 kcal·mol–1) was observed by calculated energy.

Crystal structure and Hirshfeld surface analysis of (E)-N-[(2-ethoxynaphthalen-1-yl)methylidene]-5,6,7,8-tetrahydronaphthalen-1-amine

“…There are no direct precedents for the structure of (I) in the crystallographic literature (CSD version 5.39, update of August 2018;Groom et al, 2016). However, there are several precedents for (E)-N-benzylidene-5,6,7,8-tetrahydronaphthalen-1-amine and (E)-N-[(2-ethoxynaphthalen-1-yl)methylene]aniline including 2-(4-isopropylphenyl)-1,3-diphenyl-2,3dihydro-1H-naphtho[1,2-e][1,3]oxazine (Borah et al, 2014), 2-(2-nitrophenyl)-3-(5,6,7,8-tetrahydronaphthalen-1-yl)-1,3thiazolidin-4-one (Drawanz et al, 2017) (Wu et al, 2013) and methyl (5aR,6aR,9R,-10aR)-4-benzoyl- 7-methyl4,5,5a,6,6a,7,8,9,10,10adecahydroindolo[4,3-fg]quinoline-9-carboxylate dihydrate (Lee et al, 2015).…”

Synthesis of Novel Thiazolidin‐4‐ones and Thiazinan‐4‐ones Analogous to Rosiglitazone

“…This factor shows the diversity that the effect of these groups may have on biological activity. The literature reported that different reaction times are needed according to amine ; however, all compounds were obtained in the same reaction times in this work (18 h). The thiazolidin‐4‐ones 9a–l and thiazinan‐4‐ones 10–g were purified by column chromatography using as adsorbent, the silica gel (0.2–0.5 mm) and as eluent, a solution of hexane/ethyl acetate (8:2 to 1:1), and yields ranged from 18% to 76% and 16% to 84%, respectively.…”

Amine‐carbon disulfide promoted synthesis of novel benzo[e][1,3]thiazepin‐5(1H)‐one derivatives

“…Regarding the significance of benzothiazepinone derivatives, several efforts have been focused on the synthesis of this class of organic compounds. The reaction of 2‐aminothiophenol with α,β‐unsaturated carboxylic acid derivatives using tetrabutylammonium fluoride, the reaction of aldehydes and 2‐mercapto‐ N ‐phenylacetamide and the reaction of thiosalicylic acid with epoxides are a number of reported methods for the synthesis of benzothiazepinone derivatives. In addition, the multicomponent and solid phase syntheses are widely used for the synthesis of this class of compounds.…”