New Methods for the Synthesis of Imidazoline N-Oxides.-The δ3-imidazoline 3-oxides (VII) are obtained in moderate yields by the reaction of syn-2-bromoacetophenone oxime (IV) with the aromatic Schiff bases (III), prepared from the amines (I) and aldehydes (II). The 5,6-dihydro-4H-1,2,5oxadiazines (VIII) are formed as the by-products. The reaction sequence is also performed as a one-pot procedure. In some cases, the intermediates (V) and (VI) can be isolated. -(COSKUN, N.; SUEMENGEN, D.; Synth. Commun.

The Preparation and Rearrangement of 3-Pyridyl-4-alkyl (or aryl)-1,2,4-oxadiazole-5(4H)-thiones. -In view of the biological importance of oxadiazolethiones, some new derivatives (III) are synthesized. When heated without metallic copper as the catalyst they remain unchanged. The rearrangement (III) → (IV) is also sensitive to silver catalysis; however, the reaction takes a longer time. -(DUERUEST, Y.; AGIRBAS, H.; SUEMENGEN, D.; Phosphorus, Sulfur Silicon Relat. Elem. 62 (1991) 1-4, 47-51; Dep. Chem., Karadeniz Tech. Univ., Trabzon, Turkey; EN)

Synthesis and Methylation of Some 1,2,4-Thiadiazole-5-thiones.-The synthesis and IR characterization of the title compounds (V) and ( X) is described (yield of (VIII) not given). The direct synthesis of ( V) from (I) and CS2 fails. -(AGIRBAS, H.; DUERUEST, Y.; SUEMENGEN, D.; Phosphorus, Sulfur Silicon Relat.

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1992 ring closure reactions ring closure reactions O 0130 -069The Reaction of Amidoximes with Chloroacetyl Chloride.-In a straight-forward synthesis outlined in the reaction scheme, the 1, 2,4-oxadiazoles (III) or 1,2,4-oxadiazines (V) are obtained by cyclocondensation processes of the title compounds. In both cases, the reaction is limited to the given substituents, and the formation of some by-products is observed. -(AGIRBAS, H.; SUEMENGEN, D.; DUERUEST, Y.; DUERUEST, N.; Synth. Commun.