Selenophenes, cyano

Selenophene, bis(TV-chlorothioimino)-molecular structure, 4, 939 Selenophene, 2-bromo-mercuration, 4, 946 Selenophene, 3-bromo-lithiation, 4, 949 synthesis, 4, 955 Selenophene, 3-bromo-2-lithio-synthesis, 4, 955 Selenophene, bromonitro-debromination, 4, 78 synthesis, 4, 955 Selenophene, 2-chloromethyl-solvolysis, 4, 952 Selenophene, 3-cyano-synthesis, 4, 955 Selenophene, deutero-deuterium exchange, 4, 949 Selenophene, 2,5-diacyl-3,4-dihydroxy-synthesis, 4, 964... 

Cyano-substituted selenophenes are valuable precursors of formyl derivatives.89 They are also used as starting materials for the preparation of carboxylic acids and their derivatives.128 By treating the cyano compounds with hydrogen selenide, selenoloamides (101) were obtained. As shown in... 

Experimental precautions are required for NMR measurements in this group because the adducts rapidly undergo ring opening. The NMR spectra of the selenophene adducts in solution are similar to those of the corresponding thiophene adducts. The H-NMR data for adducts 142-145, as obtained from dinitro and cyanonitroselenophene derivatives, are reported in Table XXI. It is of interest that, unlike 2-cyano-4-nitrothiophene, its selenophene analog is converted to the anionic a-adduct by nucleophilic attachment at the unsubstituted C-5 position without any competition from a reaction at the CN side chain.169... 

The dipole moments of some simple halogeno-, cyano-, and formyl-selenophens have been measured and the conformations of these compounds have been discussed. Through a study of the n.m.r. spectrum of selenophen in lyotropic mesophase, the ratios of the interproton distances were calculated from the direct couplings and found to be in good agreement with the corresponding values calculated from microwave data. ... 

Some 5-nitro-2-thienyl-pyrazoles have been prepared for a study of their antimicrobial activity. The oximes of thienyl- and selenienyl-carboxamides, prepared from the nitriles and hydroxylamine, give 1,2,4-oxadiazoles by reaction with triethyl orthoformate in BFs etherate. Starting from cyano-thiophens and cyano-selenophens, thienyl- and selenienyl-triazoles and tetrazines were prepared. From the jS-diketone (184) the triheterocyclic (185) was obtained... 

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