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22nd February 2012 @ 22:39
Recovered starting material (ca. 90%), suspect sodium hydride quenched by wet THF. To be repeated.

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Synthesis of the ether-linked analogue of TCMDC-123812 from alcohol PMY 18-2 and 2-bromoacetamide.

37-1.png

Reaction Start Time: 14.45 23/02/12
Sodium hydride (60% in mineral oil, 40 mg, 1 mmol, 1.1 equiv.) was suspended in THF (5 mL) in an ice bath. PMY 18-2 (crude) was dissolved in THF (5 + 2 mL) and added portionwise to the sodium hydride suspension and the reaction allowed to warm to room temperature. After 15 minutes, 2-bromoacetamide (152 mg, 1.10 mmol, 1.1 equiv.) in THF (5 mL) was added dropwise to the pale yellow solution. The reaction turns hazy. After 1 hour, no reaction observed by TLC. Reaction left to stir over 4 days. TLC shows no change, SM only. Saturated NH4Cl(aq)) (5 mL) was added, after stirring for 5 minutes, EtOAc (10 mL) was added and the layers separated. The aqueous layer was extracted with further EtOAc (2 × 10 mL). The combined organic layers were washed with brine, dried (MgSO4) and concentrated to an orange oil (195 mg). NMR consistent with PMY 15-1/18-1 (alcohol), quite clean by 1H NMR. Suspect THF not dry enough/NaH quenched before reaction commenced.

TLC (25% EtOAc/hexane) visualised with UV and vanillin:
TLC 4 days


NMR:
1H NMR


Risk and Hazard Assessment:
Risk Assessment
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Scheme
Risk Assessment
Scheme
TLC 4 days
1H NMR