Search

An easy, fast, and cheap way for the synthesis of the new 3,5-dioxo-thiazolo[2,3-a] pyrimidine-6-carbonitriles and 4,6-dioxo-pyrimido[2,1-b][1,3]thiazine-7-carbonitriles using epoxides α-functionalized.

Reaction of 2-aminothiophenol with epoxides (II) in refluxing MeCN gives regioselectivity 2-arylbenzothiazin-3-ones (III).

α-Cyano α-alkoxy carbonyl epoxides 1 react, in refluxing alcohol, with hydroxylamine hydrochloride 2 in a direct ring opening reaction to give β-alkoxy α-oximino esters 4 in good yields. We have shown that this reaction proceeds through the formation of chlorohydrons 3.

L'ouverture regioselective des 3-aryl-2-cyano-2-(methoxy et ethoxy-carbonyl)epoxydes 1 par l'acide chlorhydrique, conduit a des chlorocyanhydrines 3 substituees par OH, CN et CO 2 Me ou CO 2 Et sur le meme atome de carbone.

β-Alkoxy α-aminoacid esters and N-hydroxy α-amino esters are obtained by the reduction of easily accessible α-oximino esters.

The nucleophilic ring opening of gem -dicyanoepoxides by LiBr or Li 2 NiBr 4 , in the presence of hydroxylamine derivatives leads to new α-halo hydroxamic acids. These compounds has been used in the synthesis of α-functionalized hydroxamic acids, α-hydroxy and α-amino acids in good yields.

We have described a new and easy synthesis of triazoles, triazolopyrimidines, benzimidazoles and imidazoles variously substituted based on the reaction of imidates with diamine derivatives. The products were obtained in moderate to good yields. A general mechanism for the reactions is proposed.

The halohydrins prepared from epoxide esters, were treated with hydroxylamine derivatives. In subsequent reaction with NaOH/K2CO3/Bu4NHSO4 the N-protected β-halo α-aminoesters thus obtained were converted into N-hydroxy ariridine 2-carboxylic esters in good yields.