With thiazolyl ureas

The reaction of 2-amino-5-nitrothiazole with (3-chloroethyl isocyanate gives the corresponding thiazolyl urea (137) (Scheme 90) (298). Other examples are given in Section V.l.B, where the preparation of thiazolyl-thioureas is discussed,... 

Alkylation of bis(4-methyl-2-thiazolyl)urea (257) with dimethyl sulfate gives product 258 dimethylated on the ring nitrogens (Scheme 154) (488). Alkylation of l-alkyl-3-(2-thiazolyl)urea from its derived anion formed by NaH gives 259 (Scheme 155). 

Isocyanate, Me, 431 phenyl, 431 Isocyanates, 58 acyl isocyanates, 92 alkyl isocyanates, 92, 118 aryl versus alkyl, 118 with hydrazinothiazoles, 100, 106 with 2-imino-4-thiazolines, 125 to mesoionic compounds, 65 to thiazolyl urea, 58, 92 Isoindolenine derivative, 56 Isomerism, E-Z equilibrium, 23 Isomerization, catalyst in aji-unsaturated acids, 438... 

Ullmann synthesis, ] 15 Unsaturated acid chlorides, acylation, 49 Uranium derivatives, 154 Uranyl ions, 108 Urea, with azothiazoles. 111 to thiazolyl urea, 56 see also Thiazolyl urea Urine, 2-aminothiazoles in, 85 metabolite in, 85... 

Niridazole Niridazole, l-(5-nitro-2-thiazolyl)-2-imidazolidinone (38.1.11), is made by reacting 2-amino-5-nitrothiazol with 2-chloroethylisocyanate to make the disubstituted urea (38.1.10). Heating this compound results in an intramolecular N-alkylation reaction to form the desired imidazolidine derivative, niridazole [7-11]. 

Some diarylthioureas have been treated with chlorosulfonic acid thus N-phenyl-A -(2-pyridyl)- and iV-phenyl-A -(2-thiazolyl) thioureas 394 and 395 afforded the corresponding 4 -sulfonyl chlorides. . /V-Phenyl-A -(2-pyridyl)-thiourea 394, unlike the analogous urea 391, did not yield the 2, 4 -disulfonyl chloride and only gave the 4 -sulfonyl chloride. The larger steric size of the sulfur as compared with the oxygen atom presumably caused too much steric hindrance at the ortho-position of the phenyl ring to permit disulfonation. ... 

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