S. S. Novikov

Chemistry of bicyclic ureas. 5. Synthesis of 2,4,6,8-tetraazabicyclo[3.3.0]-3-octanone-7-thiones

ConclusionsA convenient method was developed for the synthesis of 2,4,6,8-tetraazabicyclo[3.3.0]-3-octanone-7-thiones by reacting the 4,5-dihydroxy- and 4,5-dimethoxy-2-imidazolidinethiones with substituted ureas.

Chemistry of bicyclic ureas 6. Synthesis of 2,4,8,10-tetraazabicyclo [4.4.0]-3,9-decanediones

ConclusionsA method was developed for obtaining 2,4,8,10-tetraazabicyclo[4.4.0]-3,9-decanediones, which contain aromatic, alkaryl, and heteroaromatic substituents in the 7 position, by the condensation of 6-ureidohexahydro-2-pyrimidinones with the appropriate aldehydes in the presence of cationite KU-2 in the acid form.

The chemistry of bicyclic bisureas. 4. Reduction of bicyclic bisureas and their O-alkyl derivatives

Conclusions1.When LiAlH4, is allowed to react with unsubstituted, di-, and tetra-N-alkylated bicyclic bisureas (BBU) of the octane and nonane series, reduction takes place only in the case of tetra-N-alkyl BBU, reduction of one or both carbonyl groups taking place according to the structure of the BBU.2.Reaction of non-N-alkylated O-alkyl BBU with nucleophilic reagents results in deprotonation with the formation of bicyclic isoureas.

The chemistry of bicyclic bisureas. 3. The synthesis and hydrolytic stability of the difluoroborate salts of 3,7-diethoxy-2,6-diaza-4,8-diazoniabicyclo[3.3.0]octane-3,7-dienes and 3,7-diethoxy-2,6-diaza-4,8-diazoniabicyclo[3.3.1]non-ane-3,7-dienes

Conclusions1.Unsubstituted and tetra-N-methyl-substituted bicyclic bisureas (BBU) of the octane and nonane series on reaction with triethyloxonium fluoroborate form O-alkylation products at both carbonyl groups, namely the difluoroborates of 3,7-diethoxy-2,6-diaza-4,8-diazoniabicyclo[3.3.0]octane-3,7-dienes and 3,7-diethoxy-2,6-diaza-4,8-diazoniabicyclo[3.3.1]nonane-3,7-dienes.2.On hydroylsis of the O-alkylation products of tetra-N-methyl-substituted BBU, the reaction resulting in the fission of one of the rings predominates.

Structure of condensation product of ethyl orthoformate with acetamide

Independent of the reaction conditions employed, trisacetylaminomethane is formed when ethyl orthoformate is reacted with acetamide.

Behavior of trisacetylaminomethane in trifluoroacetic acid

1. n nA study was made of the behavior of trisacetylaminomethane in trifluoroacetic acid. n n n n n2. n nAll of the trisacetylaminomethane is rapidly and completely hydrolyzed to a mixture of acetamide and formylacetamide when an equimolar amount of water is present in the acid. Under the conditions where the amount of water present is insufficient for complete hydrolysis, or if it is absent, the corresponding amount of trisacetylaminomethane remains in solution.

Synthesis and some properties of 1, 3, 5-trinitrocyclohexane

A method was developed for the synthesis of 1,3,5-trinitrocyclohexane and some of its properties were studied.