Studies on the reactivity of some N‐aryl‐ and N‐heteroaryl‐N'‐alkylthioureas towards electrophilic reagents. Synthesis of new N‐pyridylthioureas and thiazolines maría

Abstract

Here in we describe our findings about the behaviour of some N-aryl-and N-heteroaryl-N'-alkylthioureas towards electrophilic reagents. In acid medium, the treatment of thioureas bearing aryl groups with 4-chloropyridine in 2-propanol yielded N-aryl-N-(4-pyridyl)-N'-alkylthioureas and N-aryl-N'-alkylureas, whereas the heteroarylthioureas tested under similar reaction conditions afforded N-heteroaryl-N'-alkyl-O-(2-propyl)isoureas. The reaction of N- (5,6,7,8-tetrahydronaphth-1-yl)-and N-(2-benzimidazolyl)-N'-butylthiourea with propargyl bromide in acid medium led to the formation of 2-butylimino-3-arylthiazolines, in a regioselective way. However, when this reaction was carried out in basic conditions the regioselectivity failed and a mixture of isomeric thiazolines was obtained. The Z-or E-configuration of the imino group of the synthesized thiazolines was studied by molecular modelling and by selective nuclear Overhauser experiments in nuclear magnetic resonance.

Thiourea and Guanidine Compounds and Their Iridium Complexes in Drug‐Resistant Cancer Cell Lines: Structure‐Activity Relationships and Direct Luminescent Imaging

“…Monosubstitution of 1,1’‐thiocarbonyldiimidazole was achieved by reaction with substoichiometric 2‐aminobenzimidazole in acetonitrile. The second imidazoyl unit was displaced by a selection of amines (n‐propylamine, n‐butylamine, n‐hexylamine, and benzylamine) in the presence of dimethylaminopyridine (DMAP) in dimethylformamide (DMF) to give compounds 1S to 4S in 63–81 % yield after purification . Portions of these compounds were converted to the corresponding guanidines by reaction with mercury(II) oxide and methanolic ammonia in chloroform to give 1N to 4N in 40–65 % yield .…”

O-Pyrazolylpropynyl-Hydroxylamines as Versatile Intermediates in the Synthesis of Compounds of Pharmacological Interest

“…The analytical and synthetic methodologies were performed by using the facilities at our Institute as described in a recent work. 27 Most starting materials were commercially available products and were used without further purification. 2,4,6-Trimethylbenzoyl chloride was obtained by refluxing the commercially available acid with thionyl chloride for 8 h. 4-Iodo-3,5-dimethyl-1H-pyrazole (mp 136-137 °C (Lit.…”