Synthesis of Some New Arylmethylidene Steroidal Compounds

Abstract

An efficient method for the formation of new arylmethylidene steroidal compounds by the reaction of ketones with 4-(N,N-dimethylamino)benzaldehyde is described.

Ultrasound-assisted synthesis of benzothiazepines and assessment of theirin vitroacetylcholinesterase inhibition activity

“…In the 13 C NMR spectrum of compound 4, the signals appearing between δ 113.1 and 143.1 ppm attributed to aromatic carbons while the carbon of C = N appeared at δ 167.5 ppm clearly indicated the formation of C = N which also supports the formation of compound 4. The spectral studies are in agreement with the possible structures (4 and 4a), but the proposed mechanism (50-52), IR bands, and the absence of NH grouping signal in the 1 H NMR (50)(51)(52), superimposed IR, and co thin layer chromatography (TLC) with authentic sample prepared according to literature methods. It is well documented that the formation of 1,5-benzothiazepines occurs by the reaction of α,β-unsaturated ketones and 2-aminothiophenol under acid-catalyzed conditions.…”

“…The formation of 8 was assumed to proceed through the Micheal addition of sulfur in o-aminophenol on the δ-carbon double bond followed by intramolecular cyclization of -NH 2 on β-carbon atom of the unsaturated ketone (Scheme 2). All the spectral and analytical data for 4, 5, 6, and 8 are identical to those previously reported given in references [50][51][52] and supplemental material. 13 C NMR spectral data of titled compounds are reported for first time.…”

“…The benzothiazepines (4-6 and 8) are identified on the basis of physical, microanalytical (Supplemental material, Table S1), spectral (IR, 1 H NMR, and mass spectrometry [MS]) data, and comparison with authentic sample is given in the SI (50)(51)(52). This procedure provides a much more efficient and practical synthesis of the title compounds with the following advantages: significant shortening of the reaction time, higher yield, and ecofriendly as compared to the conventional methods.…”

Syntheses of 1,5-Benzothiazepines. Part 20. Syntheses of 8-Substituted-2,5-dihydro-2-(4-N-dimethylaminophenyl)-4-(4-methoxyphenyl)-1,5-benzothiazepines

“…Since the yields of the products were found satisfactory in acidic medium containing hydrogen chloride gas [23,24], this method was used for the syntheses of 2-(pdimethylaminophenyl)-4-methoxyphenyl-8-substituted-1,5-benzothiazepines (5a-e).…”

“…The imino structure (4) formed instantaneouly from the intermediate structure (3, not isolated), would have given three distinct double doublets in the ABX pattern in the range of δ 2.5-5.0 as has been observed in 2,3-dihydro-1,5-benzothiazepines [23,24]. The enamino structure is, therefore, a 2,5-dihydroform instead of 2,3-dihydro-form (imine).…”