Phenyliminooxalic acid dichloride, reaction with thioureas

Because of the structural requirements of the bielectrophile, fully aromatized heterocycles are usually not readily available by this procedure. The dithiocarbamate (159) reacted with oxalyl chloride to give the substituted thiazolidine-4,5-dione (160) (see Chapter 4.19), and the same reagent reacted with iV-alkylbenzamidine (161) at 100-140 °C to give the 1 -alkyl-2-phenylimidazole-4,5-dione (162) (see Chapter 4.08). Iminochlorides of oxalic acid also react with iV,iV-disubstituted thioureas in this case the 2-dialkylaminothiazolidine-2,4-dione bis-imides are obtained. Thiobenzamide generally forms linear adducts, but 2-thiazolines will form under suitable conditions (70TL3781). Phenyliminooxalic acid dichloride, prepared from oxalic acid, phosphorus pentachloride and aniline in benzene, likewise yielded thiazolidine derivatives on reaction with thioureas (71KGS471). 

Phenyliminooxalic acid dichloride likewise yielded thiazolidine derivatives on reaction with thioureas (71KGS471). 

Reaction of oxalyl chloride with compound 301 gives the thiazolidine-4,5-dione 302 (Scheme 146), and the same reagent with A-alkylbenzamidine 303 at 100-140G affords the l-alkyl-2-phenylimidazole-4,5-dione 304 (Scheme 147). Imi-nochlorides of oxalic acid react with N,N-disubstituted thioureas to give the 2-dialkylaminothiazolidine-4,5-dione bis-imides 305. Phenyliminooxalic acid dichloride likewise yielded thiazolidine derivatives on reaction with thioureas <1971KGS471>. 

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