- Rationalisation of patterns of competing reactivity by x-ray structure determination: Reaction of isomeric (benzyloxythienyl)oxazolines with a base
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Three isomeric (benzyloxythienyl)oxazolines 9, 11 and 13 have been prepared and are found, upon treatment with a strong base, to undergo either Wittig rearrangement or intramolecular attack of the benzylic anion on the oxazoline function to give products derived from cleavage of the initially formed 3-aminothienofuran products. This pattern of reactivity is directly linked to the distance between the two reactive groups as determined by X-ray diffraction, with the greatest distance in 11 leading to exclusive Wittig rearrangement, the shortest distance in 13 giving exclusively cyclisation-derived products, and the intermediate distance in 9 leading to both processes being observed. The corresponding N-butyl amides were also obtained in two cases and one of these undergoes efficient Wittig rearrangement leading to a thieno[2,3-c]pyrrolone product.
- Aitken, R. Alan,Harper, Andrew D.,Slawin, Alexandra M. Z.
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- Fries Rearrangement of some 3-Acetoxy- and 3-Propionyloxy-thiophenes
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The Fries rearrangement of ten 3-alkanoyloxythiophenes has been studied in dichloromethane using aluminium chloride as catalyst.An intermolecular component of the mechanism has been demonstrated by the observation of all possible mixed products in approximately equal proportions in a crossover experiment. 3-Alkanoyloxythiophenes were prepared from the corresponding 3-hydroxythiophenes and the rearrangement proceeded generally at ambient temperature to give 3-hydroxy-2-alkanoylthiophenes in good yields.This synthetic route provides a useful alternative to the Friedel-Crafts alkanoylation.The structures of both the acyl and 3-thiophenoxy moieties were found to exert an influence on the rearrangement.Acetyl esters rearranged at a faster rate than propionyl esters.An ester or cyano group in the 4-position did not interfere with the rearrangement whereas an acetyl group prevented it; two ester groups in the tiophene ring also prevent rearrangement occuring yielding 3-hydroxythiophenes in almost quantitative yield.
- Banks, Malcolm R.
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p. 507 - 514
(2007/10/02)
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- Thiophene compounds and their manufacture
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New thiophene compounds and a new process for the manufacture of thiophene compounds by dehydrogenating dihydrothiophene with certain halogen compounds. The products are starting materials for the manufacture of pharmaceuticals, dyes and plant protection agents and, in particular, for the manufacture of additives to foodstuffs, feeds, beverages and pharmaceuticals.
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- Aromatization of Dihydrothiophenes. Thiophenesaccharin: A Sweet Surprise
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Sulfuryl chloride has been shown to be highly effective in the dehydrogenation of 3,4-disubstituted-2,5-dihydrothiophenes and 2,3-disubstituted-4,5-dihydrothiophenes, in which the 3,4 and 2,3 substitutents are part of a β-keto carbonyl functionality or it
- Rossy, Phillip A.,Hoffmann, Werner,Mueller, Norbert
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p. 617 - 620
(2007/10/02)
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- 4H-Thieno[3,4-b][1,4]benzodiazepines
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This disclosure describes substituted 9-(4-methyl-1-piperazinyl)-4H-thieno[3,4-b][1,4]benzodiazepines which possess analgesic and anti-depressant activity and are also useful as anti-psychotic or neuroleptic agents.
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- 3,4-Disubstituted thiophenes
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This application discloses novel substituted 4-(alkoxy or alkanoyloxy)-3-thiophenecarboxylic acids, esters, and amides which possess analgesic and antipyretic activity in warm-blooded animals.
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- Thieno[3,4-b][1,5]benzoxazepin-10-ones and thieno[3,4-b][1,5]benzothiazepin-10-ones
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This disclosure describes novel substituted thieno[3,4-b][1,5]benzoxazepin-10 (9H)-ones and thieno[3,4-b][1,5]benzothiazepin-10(9H)-ones which are useful as intermediates for the preparation of 10-[4-(substituted)-1-piperazinyl]thieno[3,4-b][1,5]benzoxaze
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- 10-(Piperazinyl)thieno[3,4-b][1,5]benzoxazepines and 10-(piperazinyl)thieno[3,4-b][1,5]benzothiazepines
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This disclosure describes 10-[4-(substituted)-1-piperazinyl]thieno[3,4-b][1,5]benzoxazepines and 10-[4-(substituted-1-piperazinyl]thieno[3,4-b][1,5]benzothiazepines useful as anti-psychotic or neuroleptic agents.
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