197. Thionaphthen derivatives. Part III. Characterisation of some 5-substituted derivatives

Abstract

References 2 and 5 are regarded as Parts I and I1 of this series.

Spectroscopic properties and photophysics of the synthesized compound 5-nitro-benzo[b]thiophene-2-carboxylic acid in non-polar/polar media and in the presence of TiO2 nanoparticles

“…The synthesis of the compound 5NBTC has been made following the procedures described by Martin-Smith and others [13,14]. The characterization of the sample made from this procedure has already been described by them to test the purity of the sample whose reported melting point (242 1C) and NMR data correspond very close to those of the compound we synthesize.…”

“Abnormal” bromination reaction selectivity of 5-diarylamino-2-methylbenzo[b]thiophene caused by a “non-planar” conjugated model: Synthesis and theoretical calculation

“…According to the experiments in literatures [9][10][11][12][13][14][15][16][17][18], 5-substituted-2-methylbenzo [b]thiophene derivatives (Fig. 1a) generally had a fixed active position named as ''normal'' position (3-position of thiophene ring), whatever the 5-substituent was electron-accepting or electron-donating group (Table 1) [9][10][11][12][13][14][15][16][17][18]. The relatively higher activity of electrophilic substitution of thiophene ring may be the reasonable explanation for the selectivity.…”

Microwave-assisted synthesis of 3-aminobenzo[b]thiophene scaffolds for the preparation of kinase inhibitors

“…20,37 With such a range of biological properties, there is a continuing interest in the search for new methods to access substituted benzothiophenes. [40][41][42][43] The 5-endo-dig halocyclisation of ortho-alkynylaryl thiophenol derivatives offers an alternative approach, [44][45][46][47][48] but this requires installation of an alkyne by metal-catalyzed cross-coupling followed by cyclisation, mediated by a halogen-containing electrophile, so can exhibit a number of inherent disadvantages. 39 However, methods for the synthesis of 3-halobenzo[b]thiophenes are currently fairly limited.…”

“…40 The condensation of methyl thioglycolate with 2-chloro-5-nitrobenzaldehyde (9) under basic conditions gave methyl 5-nitrobenzo[b]thiophene-2-carboxylate (10) in high yield (Scheme 2). 40 The condensation of methyl thioglycolate with 2-chloro-5-nitrobenzaldehyde (9) under basic conditions gave methyl 5-nitrobenzo[b]thiophene-2-carboxylate (10) in high yield (Scheme 2).…”

“…40 The condensation of methyl thioglycolate with 2-chloro-5-nitrobenzaldehyde (9) under basic conditions gave methyl 5-nitrobenzo[b]thiophene-2-carboxylate (10) in high yield (Scheme 2). 40 Saponification, again conducted by microwave dielectric heating, under basic conditions was complete in 3 min at 100°C and gave the carboxylic acid 11 in excellent yield. 30,32,33,37,52 Given that elevated temperature has promoted this, 53,54 and a closely-related process for the synthesis of 2-acetylbenzothiophenes, 55 we carried out this transformation under microwave irradiation at 90°C to give the benzothiophene 10 in good yield, whilst shortening the reaction time from 17 h to 15 min.…”