An environmentally benign solvent/catalyst-free one-pot synthesis of N-substituted phthalimides via Aza-wittig reaction

For the first time an environmentally benign solvent/catalyst-free protocol for the synthesis of a variety of N-substituted phthalimides is submitted. It involves a one-pot coupling of nascent phosphazene generated in situ with phthalic anhydride. The protocol is novel in (1) avoiding toxic solvents, (2) no catalyst is employed and (3) no isophthalimide is formed as noted in the prevailing solution phase/catalysed methodology.     

Solvent-free protocol for amide bond formation via trapping of nascent phosphazenes with carboxylic acids

A solvent-free synthesis of amides via the coupling of phosphazenes with carboxylic acids is reported. Increasing the rate of heating either by microwave irradiation or conventional heating results in multifold increase in the rate of amide bond formation. Synthesis of a library of amides including a potent antitumour candidate has been accomplished.     

6,7‐Dihydrodibenzo[e,g]azulen‐8(5H)‐one and 12,13‐dihydrobenzo[e]­napth­[2,1‐g]­azulen‐14(11H)‐one

In the structures of the title compounds, 6,7‐di­hydro­dibenzo[e,g]­azulen‐8(5H)‐one, C₁₈H₁₄O, (I), and 12,13‐di­hydro­benzo[e]­napth­[2,1‐g]­azulen‐14(11H)‐one, C₂₂H₁₆O, (II), the azulene group is in a boat‐envelope conformation. The structures are stabilized by weak C—H?O interactions.     

Crystal Structure and Conformation Study of 3-Methyl-2, 6-bis (4-chlorophenyl) Piperidin-4-one Thiosemicarbazone Derivative

Abstract  

The 1, 3-dipolar cycloaddition reactions with trans azomethine ylide produce spirooxindole derivatives, which are active against certain bacterial pathogens. Spirooxindole ring systems have a very important place in medicinal chemistry because they are the central skeleton for numerous alkaloids and have potential biological activity. This newly synthesized target molecule, PSSPI was crystallized and its X-ray crystal structure has been derived. The crystallographic data of PSSPI are: C₃₄H₃₈N₂O₃; M.W = 522.7, Monoclinic, P2₁/a, with cell parameters a = 11.959(6) ?, b = 19.308(3) ?, c = 13.452(6) ?, β = 107.81(4)°; V = 2957(2) ?³, Z = 4, D _cal = 1.174 mg/m³, λ (Mo K _α ) = 0.71073 ?. Based on the crystal structure, the piperidine, pyrrolidine and cyclohexanone rings adopt half-chair, envelop and twisted sofa conformations respectively. The rings oxindole and cyclohexanone are parallel to each other but perpendicular to the pyrrolidine ring. C–H···N, C–H···O and N–H···O types of intra and intermolecular interactions control the molecules in the crystal packing.     

Structural characterization of 2,6-di(2-thioenyl)-3,5-dimethyl piperidin-4-one (DTMP) in solution and solid state

The structure of the title compound, DTMP (C₁₅H₁₇NS₂O), has been investigated in solution and in the solid state by IR, NMR and X-ray methods. The crystal structure was solved by direct methods and refined by least-squares procedures to anR-factor of 0.073. The piperidine ring adopts achair conformation. The methyl and thioenyl rings are in theequatorial position. The angle between the best plane of the piperidine ring and the thioenyl rings A and B are 88.1(1)° and 89.5(1)°, respectively.DCB contribution No. 846     

Crystal and molecular structure of 2,6-di (o-chloro)phenyl-3,5-dimethyl-N-nitrosopiperidin-4-one(NOCDMPO)

The title compound (C₁₉H₁₈O₂N₂Cl₂) crystallized in the monoclinic space groupP2₁/n witha=13.062(2),b=10.931(2),c=13.120(2)Å, and=104.57(1)°. The structure was solved by direct methods and refined toR=0.047 for 2776 reflections. The piperidine ring assumes a distorted boat conformation. The angle between phenyl rings is 78.98(7)°. The nitroso group is oriented by 138.22(7)° to the best plane of the piperidine ring. The interaction between the molecules are van der Waals in nature.DCB Contribution No. 814.