M. Mahesh

Zirconium(IV) chloride catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones

Zirconium tetrachloride catalyzes efficiently the three component condensation reaction of an aromatic aldehyde, a β-ketoester and urea in refluxing ethanol to afford the corresponding dihydropyrimidinone in high yield.

Imino Diels–Alder Reactions: Efficient Synthesis of Pyrano and Furoquinolines Catalyzed by ZrCl4

Abstract Anhydrous zirconium tetrachloride is found to be an efficient catalyst for the Imino Diels–Alder reactions of N‐benzylideneanilines with 3,4‐dihydro‐2H‐pyran and 2,3‐dihydrofuran to afford pyrano and furo [3,2‐c] quinolines in good yields.

A NEW PHASE TRANSFER CATALYST AND ITS APPLICATIONS IN ORGANIC TRANSFORMATIONS1

ABSTRACT A new quaternary ammonium bromide salt has been used for the first time in phase transfer catalysis (PTC) reactions such as oxidation of alcohols to carbonyl compounds, alkylation and esterification reactions. Improved yields and reduced reaction times have been achieved by this procedure. *IICT Communication No: 4847.

Imino Diels–Alder adducts. XII. Two pyrano[3,2-c]quinolines

The crystal structures of pyranoquinolines 9-fluoro-5-phenyl-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinoline, C18H18FNO, and 9-methyl-5-phenyl-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinoline, C19H21NO, are isomorphous. In both structures, the pyran ring is exo to the six-membered N-heterocyclic ring formed in the cycloaddition step. The torsion angles across the phenyl linkage for the two structures are -91.2 (1) and -88.3 (2) degrees. The striking feature in both crystal packings is that they do not contain the expected conventional hydrogen bonds, in spite of the presence of good hydrogen-bonding functionalities. Possible C-H...pi interactions are, however, observed.

Imino Diels–Alder adducts. I. Two furo­[3,2-c]­quinoline diastereoisomers

The structures of two diastereoisomers of 9-chloro-8-fluoro-4-phenyl-2,3,3a,4,5,9b-hexahydrofuro[3,2-c]quinoline, C(17)H(15)ClFNO, are very similar. The orientation of the furan ring, as a result of its fusion to the quinoline nucleus, constitutes the significant difference between the two structures. The dihedral angles between the furan and phenyl rings are 73.4 (1) and 63.8 (1) degrees.