New Tricyclic Aryl Quinazoline Derivatives by Suzuki-Miyaura Cross-Coupling.

A number of new deoxyvasicinone (2,3-dihydropyrrolo[2,1-b]quinazolin-9(1H)-one) and mackinazolinone (6,7,8,9-tetrahydro-11H-pyrido[2,1-b]quinazolin-11-one) derivatives with aryl substituents at C7/C8 and at C5 are reported. These compounds are rare representatives of their kind and were prepared in high yields by Suzuki-Miyaura cross-coupling reactions between 7-bromo-2,3-dihydro[2,1-b]quinazoline-9-(1H)-one, 5,7-dibromo-2,3-dihydro[2,1-b]quinazoline-9-(1H)-one or 8-bromomackinazolinone and respective arylboronic acids with palladium acetate as the catalyst. The products were characterized spectroscopically and, in addition, by X-ray crystal structure analyses in six cases.

Syntheses, crystal structures and Hirshfeld surface analysis of 2-(benzyl-sulfan-yl)-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole and 2-[(2-chloro-6-fluoro-benz-yl)sulfan-yl]-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole.

The title compounds were synthesized by alkyl-ation of 5-[(4-di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole-2-thiol with benzyl chloride or 2-chloro-6-fluoro-benzyl chloride in the presence of potassium carbonate. The yields of 2-(benzyl-sulfan-yl)-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole, CHNOS (I), and 2-[(2-chloro-6-fluoro-benz-yl)sulfan-yl]-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole, CHClFNOS (II), were 96 and 92%, respectively. In the crystal structures of (I) and (II), C-H⋯π inter-actions are observed between neighboring mol-ecules.

Syntheses, crystal structures and Hirshfeld surface analyses of -aryl-sulfonyl derivatives of cytisine.

By aryl-sulfonyl-ation of cytisine in the presence of tri-ethyl-amine, three new compounds have been obtained in good yields: (7,9)--[(4-ethyl-phen-yl)sulfon-yl]cytisine, CHNOS () {systematic name: (1,5)-3-[(4-ethyl-phen-yl)sulfon-yl]-1,2,3,4,5,6-hexa-hydro-8-1,5-methano-pyrido[1,2-][1,5]diazo-cin-8-one}, (7,9)--[(4-chloro-phen-yl)sulfon-yl]cytisine, CHClNOS () {systematic name: (1,5)-3-[(4-chloro-phen-yl)sulfon-yl]-1,2,3,4,5,6-hexa-hydro-8-1,5-methano-pyrido[1,2-][1,5]diazo-cin-8-one} and (7,9)--[(3-nitro-phen-yl)sulfon-yl]cytisine, CHNOS () {systematic name: (1,5)-3-[(3-nitro-phen-yl)sulfon-yl]-1,2,3,4,5,6-hexa-hydro-8-1,5-methano-pyrido[1,2-][1,5]diazo-cin-8-one}. The crystal structures of the compounds were determined on the basis of single-crystal X-ray diffraction data. The crystal structures of ()-() are distinguished by the arrangement of two fragments of the mol-ecule around the sulfonyl site.

Rinderidine and oblongifolidine new pyrrolizidine alkaloids from M. Popov and their absolute configurations.

The alkaloid composition of was studied, in which the pyrrolizidine alkaloids echinatine and trachelanthamine N-oxide, as well as two new quaternary salts namely rinderidine and the oblongifolidine were isolated. The structures of the isolated new alkaloids were elucidated by NMR spectroscopy. The absolute configuration of lindelofine, trachelanthamine N-oxide, rinderidine and oblongifolidine was established by single crystal X-ray diffraction as: 1 , 4 , 8 , 2', 3'; 1 , 4, 8, 2', 3'; 4 , 7, 8 , 2', 3'; 4 , 7, 8 , 2', 3' (7'', 8'') respectively.

Withanolides from L.

The compounds (17,20,22,24,25)-5β,6β:20,24-diep-oxy-4β,25-dihy-droxy-1-oxowith-2-en-26,22-olide and (20,22)-5α,14α,20-Trihy-droxy-1-oxo-6α,7α-ep-oxy-witha-2-enolide were isolated from a chloro-form extract of the aerial parts of L. (Solanaceae). Two products were isolated from the chromatographic separation extract.