Publication: 4-amino pirazol türevi bileşiklerin sentezi ve yapılarının aydınlatılması
Abstract
Nitro, azo, etilenik grup içeren bileşikler çeşitli katalizörler varlığında hidrazin hidratla redüklenmektedir. Daha önceki araştırmamızda azo bileşiklerinin hidrazin hidratla redüksiyonu 50-60ºC'de, etanollü ortamda katalizörsüz olarak yürütülmüştü. Amacımız oluşan aminleri daha önce uygulanan yöntemden daha yüksek verimle kazanmaktı. Bu çalışmada dokuz farklı 3,5-dimetilpirazol türevi bileşik sentezlenmiş ve azo grupları etanollü ortamda minumum miktarda hidrazin hidratla kullanılarak oda temperatüründe redüklenmiştir. 4-Amino-3,5-dimetilpirazol en yüksek verimle 4-(fenilazo)-3,5-dimetilpirazol'den elde edilmiştir. Pirazol halkasının bir konumunda karbamoil,2-hidroksietil ve 4-metilfenilsülfonoil grubu içern azopirazollerin redüksiyonu sonucunda da 4-Amino-3,5-dimetil pirazol elde edilmiştir. Orijinal bileşik olan4-(4-karbetoksifenilazo)-3,5-dimetil-1-(2-asetiloksietil)pirazol'ün azo grubunun redüksiyonu ile benzokain, 4-Amino-3,5-dimetil-1-(2-hidroksietil)pirazol ve 4-Amino-3,5-dimetil-1-(2-asetiloksietil)pirazol karışım halinde kazanıldı. 4-Amino-3,5-dimetil-1-(2-asetiloksietil)pirazol'ün yapısı NMR ilespektroskopisi ile tespit edilmiştir. Sonuç olarak bu çalışmada azo bileşiklerinin hidrazin hidratla incelenmiş ve yöntemin aminlerin sentezi için uygun olduğu saptanmıştır. 2.
SYNTHESIS AND STRUCTURE ELUCIDATION OF 4-AMINOPYRAZOLE DERIVATIVES Nitro,azo and ethylenic functional group containing compounds were reduced with hydrazine hydrate in the presence of several catalyst. In our previous paper , the reduction of azo compounds with hydrazine hydrate was carried out without catalyst at 50-60ºC in ethanolic medium. Our aim was yo obtain amines in higher yield compare to our aim was our applied method in the previous study. In this study nine different 3,5-dimethylpyrazole derivatives were senthesized and their azo groups were reduced using minimum quantity of hydrazine hydrate at room temperature in ethanolic medium. 4-Amino-3,5-dimethylpyrazole was obtained by reductive cleauage of 4-(Phenylazo)-3,5-dimethylpyrazole in the highest yield. As a result of the reductive of pyrazoles bearing carbamoil, 2-hydroxyethyl and 4-methylphenylsulfonyl groups in the first position of pyrazole ring, 4-Amino-3,5-dimethylpyrazole was also obtained.the reductions of orjinal compound 4-(carbetoxyphenyle)-3,5-dimethyl-1-(2-acetoxyethyl)pyrazole yielded benzocain, 4-Amino-3,5-dimethylpyrazole and 4-Amino-3,5-dimethyl-1-(2-acethyloxyethyl)pyrazole as a mixture. The structure of and 4-Amino-3,5-dimethyl-1-(2-acethyloxyethyl)pyrazole was elucidated by UV, IR and NMR spectroscopic methods. As a result of study, the reduction of azo compounds with hydrazine hydrate was investigated and it was found that the procedure was relevant for the synthesis of amines.
SYNTHESIS AND STRUCTURE ELUCIDATION OF 4-AMINOPYRAZOLE DERIVATIVES Nitro,azo and ethylenic functional group containing compounds were reduced with hydrazine hydrate in the presence of several catalyst. In our previous paper , the reduction of azo compounds with hydrazine hydrate was carried out without catalyst at 50-60ºC in ethanolic medium. Our aim was yo obtain amines in higher yield compare to our aim was our applied method in the previous study. In this study nine different 3,5-dimethylpyrazole derivatives were senthesized and their azo groups were reduced using minimum quantity of hydrazine hydrate at room temperature in ethanolic medium. 4-Amino-3,5-dimethylpyrazole was obtained by reductive cleauage of 4-(Phenylazo)-3,5-dimethylpyrazole in the highest yield. As a result of the reductive of pyrazoles bearing carbamoil, 2-hydroxyethyl and 4-methylphenylsulfonyl groups in the first position of pyrazole ring, 4-Amino-3,5-dimethylpyrazole was also obtained.the reductions of orjinal compound 4-(carbetoxyphenyle)-3,5-dimethyl-1-(2-acetoxyethyl)pyrazole yielded benzocain, 4-Amino-3,5-dimethylpyrazole and 4-Amino-3,5-dimethyl-1-(2-acethyloxyethyl)pyrazole as a mixture. The structure of and 4-Amino-3,5-dimethyl-1-(2-acethyloxyethyl)pyrazole was elucidated by UV, IR and NMR spectroscopic methods. As a result of study, the reduction of azo compounds with hydrazine hydrate was investigated and it was found that the procedure was relevant for the synthesis of amines.