Quinoxaline-2,3-dithione, reaction with

Various 3-substituted aminoquinoxaline-2-thiones have been prepared from quinoxaline-2,3-dithione. For example, treatment of the dithione with methylamine yields 3-methylaminoquinoxaline-2-thione, and the corresponding reaction with hydrazine hydrate yields 3-hydrazino-quinoxaline-2-thione. The latter compound is also obtained by treatment of 2,3-dichloroquinoxaline with thiourea and then with hydrazine hydrate. When 2-chloroquinoxaline 1-oxide is heated with thiourea in methanol at room temperature, an unidentified solid m.p. 184-185° is obtained alkaline hydrolysis of methanol-soluble products gives quinoxaline-2-thione in 41% yield. A method of some general applicability is illustrated by the preparation of the thioxo compound 4 from o-anilinoaniline (3). °... 

Cyclic derivatives have also been prepared from quinoxaline-2,3-dithiones by reaction with phosgene (COClj), thiophosgene (CSCI2), and thionyl chloride (SOCI2). 2,3-Disubstituted quinoxalines result from the reaction of the dithiones with isocyanates, isothiocyanates, and imidoyl chlorides (e.g., PhCCl=NMe). Derivatives of quinoxaline-2,3-dithiones incorporating arsenic, antimony, and tin have been prepared for example, with BujSnCl the 2,3-disubstituted quinoxaline 22 is obtained, and... 

The reaction of quinoxalin-2,3(lJf,4/J)-dithione 60 with l.ll-dichloro-3,6,9-trioxaundecane 81c unhke the reaction of quinoxalin-2,3(lff,4fl)-dione 58a with the same reagent proceeds with the formation of a mixture of products 85 and 87 (as a result of the interaction of 1 +1 ), 86 (as a result of the interaction of 1 +2 ), and 88,89 (as a result of the interaction of 2 + 2 ). As seen horn the scheme below, four of the five formed compounds are macrocycles. The isomeric structures 85,87 and 88,89 differ in accordance with the type of the alkylation of quinoxahne systems. When l,8-dichloro-3,6-dioxaoctane 81b was used instead of l,ll-dichloro-3,6,9-trioxaundecane the process proceeded with the formation of the condensation products 2 + 2 only. In this case the macrocyclic 82 contained the two N,S-alkylated quinoxaline moieties. As a result of the interaction of quinoxalin-2,3(lH,4/J)-dithione 60 with 1,5-dichloro-3-oxaoctane 81a only the acyclic products of the S-alkylation of 1+2, 2+ 3, 3+4, and 4 + 4 composition are formed in quantitative yields (2001PS169). 

Dithiolanes have been prepared by the reaction of quinoxaline-2,3-dithiones with geminal dihalogeno compounds, for example, compound 19 is formed from the reaction of the dithione and methylene di-bromide. ... 

Reaction of quinoxaline-2,3-dithiones with acylating reagents gives exclusively S-acylated products. For example, treatment of quinoxaline-... 

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