TCMDC_ArylPyrrole

 

Mnr: MNR61-70

Synthesis of N-Substituted Pyrroles Under Catalyst- and Solvent-Free Conditions, Synthetic Communications, Volume 42, Issue 16, 2012




Hazard Assessment


Procedure
MNR66-1 (0.160 g, 0.79 mmol) and 4-fluoroanilne (0.06 mL, 0.67 mmol) were heated at 120˚C for X hours.

Mnr: MNR61-70
doi:10.3184/030823409X393628




Hazard Assessment


Procedure
To a solution of MNR66-1 (recovered from MNR67-1)(0.260 g, 1.29 mmol) in dioxane (3 mL) was added a 4-fluoroanilne (0.12 mL, 1.29 mmol) and Yb(OTf)3 (0.08 g, 0.13 mmol) the resulting mixture was heated to reflux for 3 hours. The reaction mixture was allowed to cool to room temperature.

TLC of the reaction mixture at this time showed very little, if any, conversion, of the 4-fluoroanilne.

Mnr: MNR61-70
Reaction carried out using the early fraction of MNR66-1 that looked like a furan but did not have the same NMR as the major fractions.




Hazard Assessment


Procedure
To a solution of MNR66-1 (0.110 g, 0.54 mmol) in acetic acid (4 mL) was added a 4-fluoroanilne (0.03 mL, 0.36 mmol) and the resulting
mixture was heated to reflux for 3 hours. The reaction mixture was allowed to cool to room temperature.

At this stage, the column for MNR67-1 had been run and had shown no conversion to the desired product.

Mnr: MNR61-70
With the complexity of the mixture of multiple diastereomers, it's not 100% sure what the starting material is it is either MNR66-1 or MNR66-1-alt or a mixture of both.




Hazard Assessment


Procedure
To a solution of MNR66-1 (0.282 g, 1.39 mmol) in acetic acid (10 mL) was added a 4-fluoroanilne (0.05 mL, 0.56 mmol) and the resulting
mixture was heated to reflux for 3 hours. The reaction mixture was allowed to cool to room temperature and poured into water
(20 mL), and extracted with EtOAc (25 mL x 3). The combined organic layer was washed with saturated NaHCO3 solution, and brine, dried over anhydrous MgSO4, filtered and concentrated.

TLC
Reaction mixture vs 4-fluoroanilne in 100% EtOAc


Column
50-100% EtOAc/Hex

fracs 1-18 - 0.263 g - recovered starting material and traces of 4-fluoroanilne impurity, visible by TLC - 93%

fracs 19-35 - 0.164 g - - 91%

Mnr: MNR61-70



Hazard Assessment


Procedure
Crude MNR65-1 (6.7 g, mmol) was dissolved in methanol (110 mL) and was treated with hydrogen (145 psi) over Raney Nickel (1.5 mL) at room temperature for 2 hours. The reaction was then filtered through celite and concentrated at reduced pressure. With a fear of the product having a low boiling point it was attempted to distil the crude. After reaching and maintaining 140°C nothing apart from residual solvent was isolated, the crude was also changing colour so it was decided to stop this process.

Crude NMR showed a very complex set of peaks unsurprising with the number diastereomers possible but the NMR looked promising (13C more than 1H)

TLC

25% EtOAc/Hex ran twice, staining with vanillin. Yellow spot is not UV active which is in-keeping with the desired product.


Column 10-30% EtOAc/Hex.



Fracion 28 was originally concentrated and NMR'd it was very similar to the crude but the 1H was clearer. Extra signals in the OMe region and extra signals in the 13C at 90 support the fact that I may have the tri OMe compound. Need to get mass specs to prove this.

Frac 28 - 0.282 g, clear oil
Fracs 16-39 - 4.175 g, clear oil

Total recovered - 4.457 g, 21.8 mmol 66% - based on MNR66-1

Fracs 1-15 - 0.115 g
Fracs 40-55 - 1.382 g

Total mass recovered - 5.954 g