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5th September 2011 @ 07:40
Product obtained in 89% yield.


Scale up of PMY 2-2 to 10.5 mmol scale, repeat of PMY 2-3 with added hydrolysis time after quench as suggested by Bill from Creative Chemistry.

Reaction Scheme PY14.png

Experiment start time: 1710 EST 05/09/11
DMF (5.0 mL) was stirred under a nitrogen atmosphere in an ice-bath. Phosphoryl chloride (1.18 mL, 12.7 mmol, 1.2 equiv.) was added and the reaction stirred for 25 minutes. Reaction still colourless. A solution of pyrrole PMY 1-6 (2.00 g, 10.5 mmol, 1 equiv.) in DMF (5 mL) was added dropwise over 5 minutes. The reaction was removed from the ice-bath and allowed to warm to room temperature. After 45 minutes, reaction was complete by TLC. Poured over ice (100 ml). pH adjusted to 6 (approx. 20% NaOH) and left stirring overnight. In the morning, pH was 3. 20% NaOH added until pH 11 and left for a further 30 minutes. The solid was filtered and washed with water. The solid was a wet beige paste. Recrystallised (MeCN/water) to obtain a first crop of tan free-flowing powder (2.05 g, 89%).

crystals filterd
Solid prior to recrystallisation.

Hazard and Risk Assessment:
As for Scale up (3 mmol): Formylation of 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole (PMY 2-2).
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