Polystyrene-bound diaryl selenoxide and telluroxide have been prepared, which behaved as mild oxidizingagents for thiols to disulfides, phosphines to phosphine oxides, hydroquinone and catechol to p- and o-benzoquinones, and thioketones to oxo compounds. The telluroxide completed these reactions in shorter periods or under milder conditions than the selenoxide. In addition, they effected novel solvent-dependent
The reaction of t-butylhypochlorite with different thiocarbonyl compounds has been studied. Primary thioamides give 1,2,4-thiadiazole derivatives. N-Phenylthiourea gives 5-imino-4-phenyl-3-phenylamino-4,5-dihydro-1,2,4-thiadiazoline . Secondary and tertiary thioamides , N-methyl-2-thiopyrrolidinone , N,N' -dicyclohexylthiourea , N,N,N'-tri-methylthiourea , 5-ethyl-5-phenylthiobarbituric acid , xanthione
已经研究了次氯酸叔丁酯与不同的硫代羰基化合物的反应。伯硫代酰胺产生1,2,4-噻二唑衍生物。N-苯基硫脲产生5-亚氨基-4-苯基-3-苯基氨基-4,5-二氢-1,2,4-噻二唑啉。仲和叔硫酰胺,N-甲基-2-硫代吡咯烷酮,N,N'-二环己基硫脲,N,N,N'-三甲基硫脲,5-乙基-5-苯基硫代巴比妥酸,黄酮,米氏酮XXX,硫代香豆素,O- ethylthiobenzoate ,0,0-diphenylthiocarbonate ,二- p -甲苯基和ö亚苯基三硫代碳酸酯和都提供了氧类似物。N,N-二甲基-S-苯基二硫代碳酸酯产生二硫化物,三硫化物和四硫化物的混合物。一种用于转换机制提出了根据ARD和经常的CID和ASES(HSAB)原理。
Mechanism of the formation of 1,2,4-thiadiazoles by condensation of aromatic thioamides and of N-substituted thioureas
4-thiadiazole. Under the same experimental conditions, N-substituted thioureas are also condensed to 1,2,4-thiadiazole derivatives; their structure is ascertained by spectroscopicproperties and by X-ray diffraction. Some information on the mechanism of thiadiazoles formation from both starting classes of compounds, thiobenzamides and N-substituted thiourea, is collected and discussed.
N-nitrosopiperidine and N-nitroso-N-methylaniline react in acidic solution with thiocarbonyl compounds to give the corresponding carbonyl analogues. Secondary- and tertiary thioamides, xanthione, thio- and dithiobutyrolactone, thiocoumarin, certain thiourea derivatives, dithio-O,O-thiocarbonic, S,S-trithiocarbonic- and N,N disubstituted thiocarbamic esters are all converted into the corresponding O-analogues
The reactions of ketones and N-substituted thioureas, in the presence of HCl (or HBr) and DMSO afford mixtures of the title compounds which are easily separated on a silica gel column. This method avoids the classical use of α-haloketones. The mechanism of these reactions involves the enolization of ketones and the activation of thiourea sulfur, probably by oxygen transfer from DMSO.