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1st November 2011 @ 00:44
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Conversion of PMY 18-1 to its mesylate and then displacement by PMY 9-1 to form the ether analogue of TCMDC-123794.

Reaction Scheme

Reaction start time: 1400 01/11/11
PMY 18-1 (137 mg, 0.62 mmol, 1 equiv.) and triethylamine (87 μL, 0.62 mmol, 1 equiv.) were stirred in DCM (3 mL) at 0 °C. methanesulfonyl chloride (48 μL, 0.62 mmol, 1 equiv.) was added. After 20 minutes, TLC shows multiple products and SM. Water added and the mixture separated. The DCM layer was diluted (5 mL) and washed with 0.5M HCl (2 mL) then dried (MgSO4) and filtered. triethylamine (approx 0.1 mL, approx 0.72 mmol, 1.2 equiv.) was added followed by PMY 9-1 (163 mg, 0.62 mmol, 1 equiv.). Some "fizzing" observed. Earlier water and acid washes have turned bright blue within 15 minutes. TLC at 1800 (3 hours, 2nd step) shows 2 main new spots. TLC after overnight shows no change. Reaction concentrated under a stream of nitrogen.

1H NMR shows peaks similar to side-chain SM. No CH2O can be observed in significant quantity. No pyrrole type proton observed. Worth following up this reaction for another attempt.

TLC (25% EtOAc/hexane) visualised with UV and vanillin:
mesylate tlc

TLC 2nd step, 3 hours
TLC 2nd step, 17.5 hours


NMR:
1H NMR crude


Risk and Hazard Assessment:
As for Synthesis of ether-linked analogue of TCMDC-123794 (PMY 17-1)
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Attached Files
mesylate tlc
TLC 2nd step, 3 hours
amended Reaction Scheme
TLC 2nd step, 17.5 hours
1H NMR crude