Structure and base catalysed cyclization of methyl (2,6-disubstituted-4-nitrophenylsulphanyl)ethanoates
摘要:
The conformation of side chain -SCH2COOCH3 in title compounds in crystal agrees with the reactivity of these compounds in base catalysed ring closure in solution. In the 2,4-dinitro derivative, the side chain is oriented towards the unsubstituted ortho-position of benzene ring, in the case of the 2-methoxycarbonyl derivative towards this substituent. (C) 2003 Elsevier B.V. All rights reserved.
their 1H- and 13C-NMR spectra. The base catalysed ring closure of methyl 2-(methoxycarbonylmethylsulfanyl)-3,5-dinitrobenzenecarboxylate only results in an attack of carbanion on the ester group, not on a nitro group as with the other compounds prepared. The cyclisation product is methyl 3-hydroxy-5,7-dinitro-benzo[b]thiophene-2-carboxylate (11).
The conformation of side chain -SCH2COOCH3 in title compounds in crystal agrees with the reactivity of these compounds in base catalysed ring closure in solution. In the 2,4-dinitro derivative, the side chain is oriented towards the unsubstituted ortho-position of benzene ring, in the case of the 2-methoxycarbonyl derivative towards this substituent. (C) 2003 Elsevier B.V. All rights reserved.