Arenesulfonyl chlorides amino

In addition to (461), Dorn has described the imine (463) isolated from 5-amino-l-methylpyrazole and arenesulfonyl chloride (80CHE1). Upon heating, or in the presence of triethylamine, it undergoes rearrangement to the more stable 5-bis(arylsul-fonamido)pyrazoles (464). 5-Iminopyrazolines (461) react with acyl chlorides at the exocyclic nitrogen atom to afford amidopyrazolium salts (B-76MI40402). 

Arenes, polyalkyl, oxidation with per-oxytrifluoroacetic acid and boron trifluoride, 48, 89, 90 Arenesulfonyl chlorides, reaction with 3-amino-3-pyrazoline, 48, 11 Aromatic aldehydes. Mesitalde-HYDE, 47, 1... 

This procedure represents the most convenient synthesis of 3(5)-aminopyrazole. It employs readily available starting materials and gives excellent yields in all steps.5,6 />-Toluene-sulfonyl chloride can be replaced by other arenesulfonyl chlorides. 3-Imino-l-arylsulfonylpyrazolidines can be alkylated with dimethyl sulfate or with alkyl 7>-toluenesulfonates in dimethyl-formamide to give salts of l-alkyl-2-arylsulfonyl-5-amino-4-... 

Amino-l,3,4-oxadiazoles form amides with acetic anhydride, benzoyl chloride and arenesulfonyl chlorides. With phenyl isocyanate, 5-substituted 2-amino-l,3,4-oxadiazoles yield urea derivatives (71a). Using an excess of phenyl isocyanate an isocyanate (71b) is produced, and with three equivalents of phenyl isocyanate l,3,4-oxadiazolo[3,2-a]-l,3,5-triazine-5,7-diones are obtained (Chapter 4.29) (74T221). 

Acylation of 3-amino-5-methylamino-l,2,4-thiadiazole (28) with benzoyl chloride (or arenesulfonyl chlorides) introduces one acyl group when one equivalent is employed, and three when a large excess is used to produce (29) and (30), respectively (Scheme 16). With acetic anhydride, however, acylation terminates with the formation of the 3-monoacyl derivative (65AHC(5)ll9). For the mechanism of acylation, see Scheme 3. In the case of 3,5-diarylamino-l,2,4-thiadiazoles, no triacyl derivative is obtained even when excess of acylating agent is employed. Acetyl and benzoyl chlorides give monoacyl derivatives and p-toluenesulfonyl chloride forms 3,5-di(p-toIuenesulfonyl) derivatives (65AHC(5)119). 

Amino-5,6-dimethyl-1,2,4-triazine (294) reacted with arenesulfonyl chlorides to give (perhaps unexpectedly) the 5-(arylsulfonylmethyl)-l,2,4-triazines (295) (Equation (32)) <86JHC935>. 

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