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17th April 2013 @ 04:13

Formation of arryl pyrrole sulfonate salt to be chlorinated later on to produce a sulfonamide.

Reaction start time: 12:30 PM EST 13/4/13

MD 22-2 (3.0 g, 15 mmol, 1 equiv. ) and Sulfur trioxide pyridine (2.6 g, 15 mmol, 1 equiv.) were refluxed in toluene (15 mL) for 16 hours.

Reaction was concentrated under reduced atmosphere followed by addition of water and heated to 100° C, the boiling reaction was then neutralised with sodium carbonate (approx. 3 g). Water was removed under reduced pressure. A 90:10 ethanol:water mix (30 mL) was added to the residue and the solution heated to 90° C then filtered. The the dark brown solid was then concentrated  (2.1 g).

NMR showed the presence of only one methyl peak indicating a symmetrical product thus the desired product was not formed:

 

NMR:

MD_6-7_DMSO.pdf

 

Risk assessment and safety:

Same as: Synthesis of sodium 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-sulfonate (MD 6-1)

Attached Files
14th April 2013 @ 08:14

Synthesis of the aryl pyrrole core to be synthesised into a sulfonamide.

Reaction start time: 4:00 PM EDST, 12/4/13


This reaction was done in duplicates designated A and B. 4-fluoroaniline (8.8 mL, 93 mmol, 1 equiv.) and 2,5-hexanedione (10 mL, 93 mmol, 1 equiv.) were mixed and heated to 110 °C and left overnight. In the morning, the reaction was cooled to room temperature. The mixture was dissolved in hot EtOH (15 mL) after which a mixture of EtOH (10 mL) and aqueous solution of 10% citric acid (10 mL) was added. Reaction was cooled in an ice bath. The resulting brown crystals were filtered. Black contaminant remainedd in the reaction vessel so the crystals were redissolved in hot EtOH (10 mL) and a solution of 10% citric acid (10 mL) was added and the mixture was cooled with stirring. The resulting brown crystals were filtered and washed with water. Light brown crystals were isolated for reaction A (2.47 g) and reaction B (2.29 g), more crystals still appeared to be in the mother liquor.

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14th April 2013 @ 08:09
4th April 2013 @ 06:28

 

Reaction start time: 4:00 PM EST 4/4/13
MD 29-2 (15 mg, 44 mmol, 1 equiv) was dissolved in methanol followed by addition of excess aqueous ammonia (10 mL) which was then stirred for 30 minutes. After which the product was concentrated under reduced atmosphere.

 

NMR:

MD 30-1.pdf
MD_30-1.rar

 

Risk and hazard assessment:

MD 30-1 RA.pdf
Attached Files
4th April 2013 @ 06:28

Methyl ester sulfonamide was obtained in 27% yield. Product was used in MD-30.

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Formation of methyl ester sulfonamide as a step towards forming 2-(1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-sulfonamido)acetate, a possible antimalarial.

Reaction start time: 10:30 AM EST 26/3/13

Crude MD 27-4 (0.11 g, 0.30 mmol, 1 equiv.) was dissolved in pyridine (10 ml) and mixed with Glycine methyl ester (0.13 g, 10 mmol, 3.3 eq.), which was was stirred overnight at room temperature. The reaction was then concentrated under reduced pressure to give the crude product which was columned with 50:50, ethyl acetate:hexane solvent mixture to give the purified product (30 mg 0.080 mmol, 27% yield).

 

Risk and hazard assessment:

Same as second half of Synthesis of 2-(1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-sulfonamido)acetamide (MD 26-2)

Attached Files