M. F. Bundule

Octahydropyrrolo[4,3,2-m,n]acridine derivatives. I. Synthesis and molecular structure of derivatives of 2,3,4,5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]acridin-10-one, a new heterocyclic system

Heating 1,1-bis(5,5-dimethyl-1,3-cyclohexanedion-2-yl)acetone with ammonia gave a new heterocyclic compound, namely, 1,4,4,8,8-pentamethyl-2,3,4,5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]acridin-10-one. Analogously, 3,6-dimethyl-9-benzoyl-1,2,3,4,5,6,7,8-octahydroxanthene-1,8-dione gave 4,8-dimethyl-1-phenyl-2,3,4,-5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]acridin-10-one. The structures of these products were demonstrated by PMR and IR spectroscopy and x-ray diffraction analysis.

MOLECULAR CRYSTAL STRUCTURE AND CHEMICAL PROPERTIES OF 4-PHENYL-3,5-DIETHOXYCARBONYL-1,2,6-TRIMETHYL-1,2-DIHYDROPYRIDINE

The molecular crystal structure of 4-phenyl-3,5-diethoxycarbonyl-1,2,6-trimethyl-1,2-dihydropyridine has been investigated by x-ray structural analysis. The three-dimensional structural properties of the molecule have been compared against the large observed reactivity of the 3-ethoxycarbonyl group with respect to nucleophilic substitution reactions.

X-ray structural investigation of novel azabicyclic systems containing aziridine rings

Successive conversion reactions of methyl aziridine-2-carboxylate have been used to prepare novel azabicyclic derivatives, namely, 2-carbamoylmethyl-1,3-diazabicyclo [3.1.0]hexan-4-one and 2,2-dimethyl-1,3,4-triazabicyclo[4.1.0]heptan-5-one, whose structures were established unequivocally by x-ray structure analysis.

Absolute configurations of diastereomeric esters of 1,4-tetrahydrothiazine-3,5-dicarboxylic acid

The reaction of dimethyl 1,4-tetrahydrothiazone-3,5-dicarboxylate with phenyl isocyanate and phenyl isothiocyanate leads to 2,4-dioxo-3-phenyl-9-methoxycarbonyl-7-thia-1,3-diazabicyclo[3.4.O]nonane and its thioxo analog. It is shown that only the trans isomer of the starting diester undergoes the reaction.

Reaction of 1,3-thiazolidine-4-carboxylic and 1,4-tetrahydro-thiazine-3-carboxylic acid esters with isocyanates and isothiocyanates and structures of the reaction products

Abstract7-Thia-1,3-diazabicyclo[3.3.0]octane-2,4-diones and 7-thia-1,3-diazabicyclo[4.3.0]-nonane-2, 4-diones, as well as their thio analogs, were obtained by the reaction of (S)-1,3-thiazolidine-4-carboxylic and 1,4-tetrahydrothiazine-3-carboxylic acid esters with isocyanates and isothiocyanates. Intermediate reaction products, viz., heterocyclic derivatives of urea, were isolated. The three-dimensional structures of the 3-methyl-4-oxo-7-thia-1,3-diazabicyclo[3.3.0]octane-2-thione and 3-methyl-4-oxo-7-thia-1, 3-diazabicyclo[4.3.0]nonane-2-thione molecules were determined by x-ray diffraction analysis.

Preparation, molecular-crystal structure, and chemical peculiarities of the potassium salt of 3,3,6,6-tetramethyl-1,8-dioxo-1,2, 3,4,5,6,7,8,9,10-decahydroacridine-9-carboxylic acid

It was established by x-ray diffraction analysis that the crystalline title compound exists as a dimer formed by two paired potassium ions bonded to the oxygen atoms of the carboxy group and the coordinated oxygen atoms of the carbonyl groups. The solvate of the dimer with the composition 2C18H22NO4K·3H2O·CH3COCH3 is the crystallochemically independent structural unit. A shift of the electron density toward the carbonyl groups and the formation of a strong hydrogen bond between NH and the oxygen atom of the carboxylate group are observed.