O-fenilkarbamoilhidroksilamin bileşiğinin sentezi bazı sentetik uygulamaları
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Date
2004-06-29
Authors
Parlar, Aydın
Journal Title
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Publisher
Uludağ Üniversitesi
Abstract
Bu çalışmada O-arilkarbamoilhidroksilamonyum tosilat yüksek verimle sentezlendi ve reaksiyonları rapor edildi. O-Arilkarbamoillenmiş hidroksilamonyum tosilat oda sıcaklığında etanol içinde ketonlarla reaksiyona sokularak karşılık gelen karbamoillenmiş oksimler 2 kantitatif verimlerle elde edildiler. Halkalaşma sağlamak üzere KOH ve LDA'mn farklı miktarlanyla etkileştirilmeleriyse başarısız oldu. Bunun yerine karbamoillenmiş oksimler 2 N,N-dialkil-N'-fenil ürelerle THF veya eter içinde oda sıcaklığında reaksiyona sokulduğunda kısa sürede iyi verimlerle 1:1 moleküler komplekslerin 5 oluştuğu ilk defa gösterildi. Moleküler kompleksler 5a-e izole edilerek analitik ve spektral yöntemlerle karakterize edildi. 5a kompleksinin yapısının anlaşılması için X-ışını analizi yöntemi kullanıldı. Kompleks karbamoillenmiş oksimin karbamat NH'ı ve üre oksijeni ile üre NH'ı ve karbamoil karbonili arasındaki hidrojen bağlarıyla oluşmaktadır. [l,2,4]-Oksadiazolidinonlar 2 bileşiklerinin halkalaşmasıyla elde edilemeyince aromatik aldehidlerin metanol içinde karşılık gelen sekonder aminlere NaBH4 ile indirgen aminasyonu ve sonra H2O2-WO42" sistemi ile karşılık gelen nitronlarm 6 eldesini içeren sentez yolundan elde edildi. Nitronlarm yapılan hidroksilamin hidroklorürle reaksiyonlan yoluyla kolayca belirlendi. C-Fenil sübstitüe olmayan ya da elektron salan sübstitüent taşıyan nitronlar 6a,c,f fenil izosiyanatla kısa sürede reaksiyona girerek yüksek verimlerle karşılık gelen [l,2,4]-oksadiazolidinonlan 8 verirken, elektron çeken sübstitüent taşıyan nitronlar 6b,d,e daha düşük verimlerle karşılık gelen oksadiazolidinonlan verdi. Oksadiazolidinonlar 8a,c,f dietil amin birlikteliğinde ısıtıldıklarında kısa sürede karşılık gelen Schiff bazı ve benzaldiminleri verirken oksadiazolidinonlar 8b,d,e benzeri değişim vermedi. Dietil aminle 8d,e bileşiklerinin ısıtılmasıyla kompleks karışım oluşurken 8b bileşiği karşılık gelen amidin'i verecek şekilde bozundu.
In this study the synthesis of O-arylcarbamoylhydroxylammonium tosylate in high yield and its reactions are reported. 0-Arylcarbamoylated hydroxylammonium tosylate react with ketones in ethanol at room temperature to give the corresponding carbamoylated oximes 2 in quantitative yields. Attempts to induce cyclization using bases as KOH and LDA at different conditions failed. Instead it was shown for the first time that carbamoylated oximes 2 form 1:1 molecular complexes 5 with NJV- dialkyl-iV-phenylureas when stirred in THF or ether at room temperature for short time in good yields. The molecular complexes 5a-e were isolated and characterized by analytical and spectral means. X-ray crystallographic analysis for complex 5a was performed. The complex was shown to form through the hydrogen bond formed between the carbamate NH of the carbamoylated oxime and the urea oxygen and urea NH and carbamate carbonyl. The cyclic 1,2,4-oxadiazolidinones inaccessible by the cyclization of compounds 2 were accessed by a method involving the reductive amination of corresponding aldehydes to the corresponding secondary amines using NaBHi in methanol in good yields. Oxidation of the latter with H2O2-WO42" to the corresponding nitrones 6 the structures of which were easily determined through reacting them with hydroxylamine hydrochloride. Nitrones 6a,c,f with unsubstituted C-phenyl or having electron donating substituents underwent reaction with phenyl isocyanate for short time with high yields to give the corresponding 1,2,4- oxadiazolidinone 8, while 6b,d,e having electron withdrawing substituents gave corresponding oxadiazolidinone in moderate yields. Oxadiazolidinones 8a,c,f underwent fragmentation with diethylamine for short time to give the corresponding Schiff base and benzaldimine while oxadiazolidinones 8b,d,e remain unchanged at this conditions. Prolonged heating of 8d,e in the presence of diethylamine led to complex mixtures. In the case of 8b the corresponding amidine was the main product of the reaction.
In this study the synthesis of O-arylcarbamoylhydroxylammonium tosylate in high yield and its reactions are reported. 0-Arylcarbamoylated hydroxylammonium tosylate react with ketones in ethanol at room temperature to give the corresponding carbamoylated oximes 2 in quantitative yields. Attempts to induce cyclization using bases as KOH and LDA at different conditions failed. Instead it was shown for the first time that carbamoylated oximes 2 form 1:1 molecular complexes 5 with NJV- dialkyl-iV-phenylureas when stirred in THF or ether at room temperature for short time in good yields. The molecular complexes 5a-e were isolated and characterized by analytical and spectral means. X-ray crystallographic analysis for complex 5a was performed. The complex was shown to form through the hydrogen bond formed between the carbamate NH of the carbamoylated oxime and the urea oxygen and urea NH and carbamate carbonyl. The cyclic 1,2,4-oxadiazolidinones inaccessible by the cyclization of compounds 2 were accessed by a method involving the reductive amination of corresponding aldehydes to the corresponding secondary amines using NaBHi in methanol in good yields. Oxidation of the latter with H2O2-WO42" to the corresponding nitrones 6 the structures of which were easily determined through reacting them with hydroxylamine hydrochloride. Nitrones 6a,c,f with unsubstituted C-phenyl or having electron donating substituents underwent reaction with phenyl isocyanate for short time with high yields to give the corresponding 1,2,4- oxadiazolidinone 8, while 6b,d,e having electron withdrawing substituents gave corresponding oxadiazolidinone in moderate yields. Oxadiazolidinones 8a,c,f underwent fragmentation with diethylamine for short time to give the corresponding Schiff base and benzaldimine while oxadiazolidinones 8b,d,e remain unchanged at this conditions. Prolonged heating of 8d,e in the presence of diethylamine led to complex mixtures. In the case of 8b the corresponding amidine was the main product of the reaction.
Description
Keywords
O-Karbamoillenmiş oksim, Moleküler kompleks, Nitron, [ 1,2,4] -oksadiazolidinon, O-Carbamoylated oximes, Molecular complex, Nitrone, [1,2,4]- oxadiazolidinone
Citation
Parlar, A. (2004). O-fenilkarbamoilhidroksilamin bileşiğinin sentezi bazı sentetik uygulamaları. Yayınlanmamış yüksek lisans tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.