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21st October 2016 @ 04:09
SM/P 2,3-dimethylpyrazine-N,N’-dioxide POCl3 Dichloro-methylpyrazine
mw 140.14 153.33 162.9
Equiv 1 3 1
mmol 2.85 8.55  
mg 0.4 1.31  
mL   2.15  
g/mL   1.64  

 

October 21, 2016

The crude product from Alternate Methylation Step 1: 2,3-Dimethylpyrazine-N,N'-dioxide synthesis was transferred into a 100 mL round bottom flask and dried on the high vacuum. 2.2 mL of POCL3 were added dropwise and the reaction was heated to 70°C under reflux for one hour. The resulting mixture was quenched with 20% NaOH and the product was extracted with diethylether. 

18th October 2016 @ 19:22
SM/P 2,3-dimethylpyrazine OXONE 2,3-dimethylpyrazine-N,N'-dioxide
mw 108.14 307.38 140.14
Equiv 1 2 1
mmol 18.7 40.3 14.27
g 2.02 24.8 2.02

October 4th, 2016

In an r.b. flask, 2.02 grams of 2,3-dimethylpyrazine was dissolved in 20 mL CH2Cl2 then stirred with 24.8 grams OXONE in 140 mL H2O for 30 hours at 25°C.  The resulting solution was extracted with CH2Cl2.  The organic layer was saved while the aqueous layer was stirred for another 24 hours with a fresh portion of about 20mL CH2Cl2 then a second organic layer was extracted.  The combined organic layers were dried over anhydrous MgSO4, then solvent was then removed under reduced pressure.  The resulting product was a beige crystal (yield: 20%, 0.40g). 

 

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22nd September 2016 @ 17:59
 

Table of Reagents

SM/P

2,6-dichloropyrazine

 

n-BuLi

2,2,6,6-Tetramethylpiperidine

 

Iodomethane

3,5-dichloro-2-methylpyrazine

mw

147.96

64.06

141.25

141.94

161.98

Equiv

1.00

2.00

2.00

1.00

1.00

mmol

6.76

13.52

13.52

6.76

6.76

mg

2000

1732

3820

1920

2188

mL

 

2.6

4.56

.84

 

g/mL

 

0.68

0.837

2.28 

 

M

 

 

 

 

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


September 18, 2016

To a solution of n-BuLi (2.6 mL, 13.52mmol) in dry THF (30 mL) was added LiTMP (3.82 g, 13.52mmol) at -78°C (in a dry ice/acetone bath). The mixture was then warmed to 0°C (water/ice bath) and stirred for 30 minutes. The reaction was cooled to -78°C, then 2,6-dichlorpyrazine (2.0 g, 6.76mmol) was added in 20 mL of THF into the reaction dropwise. The mixture stirred for 30 minutes, then CH3I (0.84 mL, 6.76 mmol) was added and the reaction was allowed to room temperature. 

September 20, 2016

The mixture was concentrated on the rotovap, and transfered into a 250 mL separatory funnel with water and DCM. The aqueous layer was extraced four times with 30 mL of DCM, then the organic layer was washed with sat. NH4CL and dH20, then dried over Na2SO4 and concentrated with the rotovap. The remaining product was left to dry overnight on the high vac. 

September 22, 2016

The crude product was purified using the Biotage flash chromatography machine. 

September 26, 2016

All of the fractions collected from the Biotage were analyzed using GC/MS and NMR. We predicted that our product was in the first set of fractions; however, GC/MS showed the mass of our starting material (2,6-dichloropyrazine), and NMR sample was taken and it showed pure, unreacted starting material. 

22nd September 2016 @ 17:05
Table of Reagents

SM/P

2,6-dichloropyrazine

 

n-BuLi

2,2,6,6-Tetramethylpiperidine

 

Iodomethane

3,5-dichloro-2-methylpyrazine

mw

147.96

64.06

141.25

141.94

161.98

Equiv

1.00

2.00

2.00

1.00

1.00

mmol

6.76

13.52

13.52

6.76

6.76

mg

2000

1732

3820

1920

2188

mL

 

2.6

4.56

.84

 

g/mL

 

0.68

0.837

2.28 

 

M

 

 

 

 

 

 

step 1 monometh.jpg

September 6, 2016

To a solution of n-BuLi (2.6 mL, 13.52mmol) in dry THF (30 mL) was added LiTMP (3.82 g, 13.52mmol) at -78°C (in a dry ice/acetone bath). The mixture was then warmed to 0°C (water/ice bath) and stirred for 30 minutes. The reaction was cooled to -78°C, then 2,6-dichlorpyrazine (2.0 g, 6.76mmol) was added in 20 mL of THF into the reaction dropwise. The mixture stirred for 30 minutes, then CH3I (0.84 mL, 6.76 mmol) was added and the reaction was allowed to room temperature. 

September 8, 2016

The mixture was concentrated on the rotovap, and transfered into a 250 mL separatory funnel with water and DCM. The aqueous layer was extraced four times with 30 mL of DCM, then the organic layer was washed with sat. NH4CL and dH20, then dried over Na2SO4 and concentrated with the rotovap. The remaining product was left to dry overnight on the high vac. 

September 13, 2016

The dry product was set up to dry transfer onto a silica gel column. The product was purified through the column. The product was concentrated and dried on the high vac overnight for the next reaction. 

 

TLC was run in 70:30 Hexanes to Ethyl Acetate 

IMG_0410.PNG
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