Unexpected Simple and Catalyst‐Free Condensation Reaction of Spiro Dihydrofurans with 2,4‐Dinitrophenylhydrazine, Thiosemicarbazide, and Hydroxylamine for the Synthesis of Novel Corresponding 4,4,6′,6′‐Tetramethyl‐3′‐aryl‐3′,5′,6′,7′‐tetrahydrospiro[cyclohexane‐1,2′‐indole]‐4′,6(1′H)‐diones: Crystal Structure

Abstract

in Wiley Online Library (wileyonlinelibrary.com).The reaction of 4 0 ,4 0 ,6,6-tetramethyl-3-aryl-3,5,6,7-tetrahydro-4H-spiro[benzofuran-2,1 0 -cyclohexane]-2 0 ,4,6 0 -trione with 2,4-dinitrophenylhydrazine, thiosemicarbazone, and hydroxylamine afforded unexpectedly novel corresponding 4,4,6 0 ,6 0 -tetramethyl-3 0 -aryl-3 0 ,5 0 ,6 0 ,7 0 -tetrahydrospiro[cyclohexane-1,2 0 -indole]-4 0 , 6(1 0 H)-diones in ethylene glycol in reflux and catalyst-free condition. The structure is characterized using FT-IR, 1 H, 13 C NMR, elemental analysis, mass spectrometer, and X-ray crystallography techniques.

A Facile and Catalyst-free Synthesis of Hexahydroacridine-1,8(2H,5H )-dione and Octahydroacridin-10(1H )-yl)thiourea Derivatives: Inter- and Intramolecular Aza-Michael addition

“…In the course of the reaction, dehydration of 1a, in the presence of hydroxylamine, obtained compound A. Then aza-Michael addition [18][19][20] The ketone carbonyl group in 1b has a stretching frequency at 1723 cm -1 . This peak is lost in the compounds 2b and 3b.…”