Viesturs Lūsis

Synthesis and isomerization of 1H-4,4a,5,9b-tetrahydroindeno- [1,2-b]pyridines

Abstract Synthesis of 1H-4,4a,5,9b-tetrahydroindeno[1,2-b]pyridines has been accomplished by catalytic hydrogenation of 4H-4a-5-dihydroindenopyridines. The isomerization of 1H-4,4a,5,9b-tetrahydroindenopyridines containing an acyl function at C-3 leads to 3H-4,4a,5,9b-tetrahydroindenopyridines in acidic medium.

Recyclization of 1,4-dihydropyridine derivatives in acidic medium

The recyclization of 1,4-dihydropyridines in aqueous-alcoholic hydrochloric acid medium proceeds with cleavage of a C-N bond and pyridine ring opening. Cyclohexenone derivatives are formed as a result of the subsequent intramolecular crotonic condensation of the acyclic intermediate. The leaving carbonyl substituents depart simultaneously with recyclization, depending on the acidity of the reaction medium.

Synthesis of novel 3-substituted benzamides related to imatinib

Twelve new 3-substituted benzamide derivatives structurally related to tyrosine kinase inhibitor imatinib have been synthesised by a Cu(I)-catalysed coupling of three previously synthesised (5-iodo-2-methylphenyl)-[4-(pyridin-3-yl)-6-perfluoroalkylpyrimidin-2-yl]amines with four synthesised 3-substituted 4-(4-methylpiperazin-1-ylmethyl)benzamides.

Synthesis of 6-t rifluoromethyl derivatives of 2-arylamino-4-(pyridin-3-yl) pyrimidines

The 6-trifluoromethyl derivative of a well known tyrosine kinase inhibitor, nilotinib, as well as some novel 6-trifluoromethyl substituted 2-arylamino-4-(pyridin-3-yl) pyrimidines were synthesised.

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

Summary Stable heterocyclic hydroperoxide can be easily prepared as a product of fast oxidation of a 1,2,3,4-tetrahydropyridine by 3O2 if the solution is exposed to sunlight. The driving force for the photoinduced electron transfer is calculated from electrochemical and spectroscopic data. The outcome of the reaction depends on the light intensity and the concentration of O2. In the solid state the heterocyclic hydroperoxide is stable; in solution it is involved in further reactions.

Acid-mediated cyclotransformations of 4a-substituted 4H-4a,5-dihydroindeno[1,2-b]pyridines as a new route to 9a-substituted 1H-fluorenes

Abstract4a-Substituted dihydroindenopyridines undergo cleavage of the C(9b)=N bond in water-containing acidic medium, resulting in the formation of diastereomeric ethyl α-acetyl-β-(2,3-dihydro-1,3-dioxo-1H-inden-2-yl)-β-phenylpropionates and 9a-substituted 1,9a-dihydrofluore-none derivatives. The cyclization of α-acetyl-β-(2,3-dihydro-1,3-dioxo-1H-inden-2-yl)-β-phenyl-propionates with benzylammonium acetate affords 3-benzylamino-1,9a-dihydrofluorenones. The methanobenzo[a]azulene compound is also found among cyclization products.