Synthesis, 19F NMR spectral studies and antibacterial evaluation of some new fluorine containing indole derivatives

A stereochemical investigation of the nucleophilic addition of methyl ethyl ketone to (E)-alkyloxindolylideneacetates

The reaction of (E)-(2-oxo-1,2-dihydroindol-3-ylidene)acetic acid esters (1) with methyl ethyl ketone in the presence of morpholine as a catalyst gave 4-oxo-2-(2-oxo-2,3-dihydro-1H-indole-3-yl)hexanoic acid esters, a diastereomeric mixture of two isomers (2A and 2B). Using aluminium oxide as a catalyst for the above reaction led to the formation of 4-oxo-3-methyl-2-(2-oxo-2,3-dihydro–1H-indole-3-yl)-pentanoic acid esters as a mixture of three isomers 3A, 3B and 3C, which upon methylation with methyl iodide in acetone and in the presence of anhydrous potassium carbonate yield the corresponding methylated products. The structural assignments of the new compounds are based on their chemical and spectroscopic properties. The stereochemical structures of 5aA, 5bB and 5aC are identified by X-ray analysis.

High Nucleophilicity of Cyclic Amidocarbene toward Aryl Isocyanates, New Approach to Spiro[azetidinone-4,3‘-indolinone] Derivatives

The nucleophilic addition of beta-lactam-4-ylidenes 2, a type of ambiphilic cyclic amidocarbene, to aryl isocyanates has been studied and their application in organic synthesis has been demonstrated. Thermolysis of spiro[beta-lactam-4,2'-oxadiazolines] 1 in the presence of aryl isocyanates afforded both N-lactam and O-lactam substituted spiro[azetidine-2-one-4,3'-indole-2'-one] derivatives 5 and 6 in the total yield of 65-86%. Upon hydrolysis, products 5 and 6 were converted into spiro[azetidine-2-one-4,3'-indole-2'-one] 9 that was analogous to known biologically active compounds.