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1st February 2012 @ 06:24
Synthesis of cyclopentane substituted thiazolidinone from PMY 13-1

reactionscheme25-1.jpg

Experiment start time: 11:00 EST 01/02/2012
Potassium carbonate (2.2 g, 2 equiv.), sodium iodide (2.5 g, 2.2 equiv.) and PMY 13-1 (1.5 g, 1 equiv.) were stirred in acetonitrile at room temperature. Cyclopentylbromide (0.92 mL) was then added dropwise and the mixture was heated to 80 °C. TLC after 5.5 hours showed formation of a single product but the reaction was not complete and the mixture was cooled and left overnight. In the morning two product spots could be seen but the reaction was incomplete so the mixture was heated again and left at 80 °C. After 24 hours the reaction was still incomplete with two product spots, and the mixture was removed from the heat and extracted with ethyl acetate (50 mL) and washed with water (3 x 20 mL) and brine (20 mL). The organic extract was concentrated under reduced pressure and TLC showed the presence of starting material and two product spots. The mixture was adsorbed onto silica and purified by column chromatography (15-20% ethyl acetate in hexane on silica) to give a pure fraction, ZYH 25-1A, and a mixed fraction, ZYH 25-1B. Proton NMR of fraction B did not appear consistent with the desired product and fraction B and the mixed fraction were discarded.

Data summary table:
Yield Melting point 1H NMR 13C NMR19F NMR IR Mass spec
25-1 ? NeedYes (pdf, H + C NMR .zip) Yes(pdf)NAYes (pdf, .dx) Need
Attached Files