Disproportionation of cyclohexanespiro-2?(1-alkyloxazolidine)s

Kukharev, B. F.; Atavin, A. S.

doi:10.1007/bf00470359

Cited by 3 publications

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“…Thus, the processes involved in the vinylation of indole and other azoles by acetylene (under pressure, at 180-220°C, in the presence of KOH, alkali metals, and their salts with azoles) and also the characteristics of the synthesized N-vinylazoles and their derivatives were actively studied from the very early years (G. G. Skvortsova, E. S. Domnina et al) [171][172][173][174][175][176][177][178][179][180][181]. Present-day methods for the production of N-vinylpyrroles 40 (B.…”

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confidence: 99%

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

Nedolya

2008

Chem Heterocycl Comp

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confidence: 99%

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

Nedolya

2008

Chem Heterocycl Comp

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“…In the present work we examined dehydration of N- 5,6, to 5,6,. We found that N-vinylindole IIa was formed in 60-68% yield when compound Ia was heated over KOH at 280°C.…”

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confidence: 97%

“…We previously reported on the formation of N-(2-hydroxyethyl)pyrroles in up to 73% yield as a result of a number of base-catalyzed redox processes, such as oxidation 2,2′-iminodietanol with cyclohexanone [4], cleavage of oxazolidines obtained from carbonyl compounds and 2,2′-iminodietanol [5,6], and oxidation of these oxazolidines with carbonyl compounds [7].…”

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confidence: 99%

“…In the recent time, the most convenient method for the preparation of these compounds is based on reaction of ketone oximes with acetylene in the system dimethyl sulfoxide-alkali metal hydroxide (Trofimov reaction) [1,2]. However, this procedure cannot be used to synthesize N-vinylpyrroles from aldehyde oximes because of concurrent dehydration of the latter to form nitriles [3].We previously reported on the formation of N-(2-hydroxyethyl)pyrroles in up to 73% yield as a result of a number of base-catalyzed redox processes, such as oxidation 2,2′-iminodietanol with cyclohexanone [4], cleavage of oxazolidines obtained from carbonyl compounds and 2,2′-iminodietanol [5,6], and oxidation of these oxazolidines with carbonyl compounds [7].It is known that some nitrogen-containing heterocyclic compounds having 2-hydroxyethyl substituents are capable of undergoing dehydration by the action of alkali to give the corresponding vinyl derivatives [8].In the present work we examined dehydration of N- 5,6, to 5,6,. We found that N-vinylindole IIa was formed in 60-68% yield when compound Ia was heated over KOH at 280°C.…”

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Synthesis of N-vinylpyrroles from N-(2-hydroxyethyl)pyrroles

2011

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SHORT COMMUNICATIONSN-Vinylpyrrole derivatives exhibit versatile biological activity and are promising as monomers and intermediate products in the synthesis of a number of compounds possessing practically important properties [1,2]. In the recent time, the most convenient method for the preparation of these compounds is based on reaction of ketone oximes with acetylene in the system dimethyl sulfoxide-alkali metal hydroxide (Trofimov reaction) [1,2]. However, this procedure cannot be used to synthesize N-vinylpyrroles from aldehyde oximes because of concurrent dehydration of the latter to form nitriles [3].We previously reported on the formation of N-(2-hydroxyethyl)pyrroles in up to 73% yield as a result of a number of base-catalyzed redox processes, such as oxidation 2,2′-iminodietanol with cyclohexanone [4], cleavage of oxazolidines obtained from carbonyl compounds and 2,2′-iminodietanol [5,6], and oxidation of these oxazolidines with carbonyl compounds [7].It is known that some nitrogen-containing heterocyclic compounds having 2-hydroxyethyl substituents are capable of undergoing dehydration by the action of alkali to give the corresponding vinyl derivatives [8].In the present work we examined dehydration of N- 5,6, to 5,6,. We found that N-vinylindole IIa was formed in 60-68% yield when compound Ia was heated over KOH at 280°C. The reaction was accompanied by formation of an appreciable amount of a polymeric product insoluble in water (as still residue). Our attempts to carry out the reaction under reduced pressure almost always resulted in foaming of the alkali melt, its ejection from the flask, and clogging of the descending condenser. The yield of indole IIa increased as the moisture content of KOH rose. Therefore, subsequent dehydration experiments were performed with simultaneous supply of water into the reaction mixture. When the amount of water was 10 wt % with respect to Ia, the yield of IIa reached 96%. Obviously, the reason is formation of a low-boiling azeotrope mixture of IIa with water, which shortens its contact with alkali and hampers polymerization.Likewise, from pyrroles Ib and Ic we obtained N-vinyl derivatives IIb and IIc in 94-97% yield. In the synthesis of low-boiling pyrroles IId and IIe the process was performed without addition of water and the yield of IId and IIe was 88-90%. N-Vinylpyrroles IIb-IId were isolated as colorless liquids. The same compounds obtained from ketone oximes and acetylene were described as colored liquids [2]. Initial pyrrole Ie was synthesized from the corresponding oxazolidine which was prepared in turn by condensation of isovaleraldehyde with 2,2′-iminodiethanol. Thus the proposed procedure ensures preparation of N-vinylpyrroles which cannot be obtained from aldehyde oximes and acetylene. On the other hand, the described procedure is more laborious (it includes three steps), and the yield calculated on the initial ketone is lower by 10-15% than in the synthesis through ketone oximes. RR′ = (CH 2 ) 4 (a), (CH 2 ) 5 (b); R = H, R′ = Ph (c); R = Me, R′ = Et (d...

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