Convenient Synthesis of NovelN-Substituted-5-aminothiazole Derivatives

Synthesis of 1‐(α‐Aminobenzyl)‐2‐naphthol Derivatives, their Structure in Crystal and in Solution

“…1,3,5‐Trisaryl‐2,4‐diazapenta‐1,4‐dienes 2a , 2b , 2c , 2d , 2e , 2f were prepared according to the known method . 1,3‐diarylnaphthoxazines 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j were obtained by interaction of 2‐naphthols 1 with 1,3,5‐trisaryl‐2,4‐diazapenta‐1,4‐dienes 2 following the method .…”

Stable synthetic equivalents of N-unsubstituted imines: Part 1. Synthesis

“…Compounds (VIII) form in yields from moderate to good when the corresponding aldehydes react with saturated aqueous [142][143][144][145][146] or alcoholic [146,147] ammonia solution, more rarely with ammonia solu tion in THF [148], CH 2 Cl 2 , or benzene [147] (Scheme 40). Ammonium chloride is used as a catalyst in some cases [147].…”

“…Such derivatives (VIII) may be of practical interest because some reactions of diazapentanes with nucleophiles proceed as a substitution at the C(3) atom of the substrate rather than addition to the C=N bond (for example [138,146,152]) and the resultant product involves the central aromatic fragment. [138,153,154], in THF or CH 2 Cl 2 [155] (often lithium [154,155] or zinc [156] salts are added as catalysts); (b) on slight cooling in hexane [157].…”

1,2,3-Triazoles

“…Treated with an excess of allylmagnesium reagent, imines 702 are converted into N,N -bis(3-butenyl)amines 703 , interesting intermediates for construction of heterocyclic systems ( Scheme 109 ) <2002JOC7530> . Imines 702 , particularly with R 1 = R 2 = aryl, can be also conveniently prepared by direct condensation of aldehydes with benzotriazole and ammonia <2000JOC8077> . Treatment of imine 702 with n -butyllithium produces anion 704 that adds readily to isothiocyanates to give intermediate anion 705 .…”

“…Loss of a benzotriazole anion followed by tautomerization leads to aminothiazole 706 . This way, 5-aminothiazoles 706 bearing aryl or heteroaryl substituents at C-2 and C-4 can be easily prepared in good yields <2000JOC8077> .

Scheme 109

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