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16th June 2017 @ 15:39

Reaction Complete. Labnote book and relevent NMRs are attached. The correct ring closed product was not isolated according to NMR (see fractions 30-44).  Haverford college will not continue with the synthesis of the 6- or the 8-. The starting material, 3,5-dichloro-2-methylpyrazine, is too expensive.

 (Images in lab notebook had to be reduced for uploading purposes.)

 

Attached Files
11th April 2017 @ 13:36
New: new

3/28/2017

Reference: http://malaria.ourexperiment.org/triazolopyrazine_se/14086/Synthesis_of_5chloro34difluoromethoxyphenyl124triazolo43apyrazine_AEW_2056.html

Scheme

Smiles: ClC1=C(C)N=CC2=NN=C(C3=CC=C(OC(F)F)C=C3)N21

 (Scheme is not showing up in ELN. See attachment)

3/28/17-Ring Closing Take #2

The reaction is going be run with more PhI(OAc)2

Reagent

mass (g)

mols

Molecular Weight (g/mol)

Volume (mL)

Density (g/mL)

Product Dimethyl Benzaldehyde Rxn

0.2

0.00064

312.70

   

CH2Cl2

8.48

0.101

84.930

~7.0

1.325

PhI(OAc)2

0.4123

0.00128

322.10

   

Product Dimethyl PhI(OAc)2 Rxn

   

310.060

   
Reaction began at 9:15am. The solid reagent was yellow. The reagent dissolved easily into  DMC and the solution turned a translucent yellow. When PhI(OAc)2 was added there was no change to the solution.

3/30/2017

  1. Reaction was stopped at 8:30 on 3/30/17. The solution was translucent yellow and had viscosity similar to water.

  2. Added saturate aqueous solution of sodium hydrogen carbonate (10 mL)

  3. White solid formed in the aqueous layer.

  4. Drained organic layer

  5. Washed aqueous layers with 10 mL DCM twice times.

  6. Combined the organic layers, washed with 10 mL of saturated aqueous sodium hydrogen carbonate two times,

       7. Organic layer was then dried in sodium sulfate.

4/1/17

     9. Sodium sulfate was gravity filtered. The organic layer was yellow

    10. Organic layer was then rotovapped to afford a yellow oil that quickly became crystalline.

 

Open= Opened Ring

Phi = PhI(OAc)2

Co= co Spot

Closed= Closed ring product.

Silica gel plate

50/50 hexane to ethanol


Attached Files
11th April 2017 @ 13:24
New: new

Reaction was run on 2/17/2017.

Reference

Scheme

Smiles: ClC1=C(C)N=CC2=NN=C(C3=CC=C(OC(F)F)C=C3)N21

 (Scheme is not showing up in ELN. See attachment)

Table of Reagents (Ring-closing)

         

Reagent

mass (g)

mols

Molecular Weight (g/mol)

Volume (mL)

Density (g/mL)

Product Dimethyl Benzaldehyde Rxn

0.2

0.00064

312.70

   

CH2Cl2

8.48

0.101

84.930

~6.4

1.325

PhI(OAc)2

0.2237

0.00069

322.10

   

Product Dimethyl PhI(OAc)2 Rxn

   

310.060

   

The product from the last step (0.2g, .64 mmol), (E)-2-chloro-6-(2-(4-(difluoromethoxy)benzylidene)hydrazineyl)-3,5- monomethylpyrazine, was combined with CH2Cl2 (6.4 ml) while stirring in a round bottom flask at room temperature.  PhI(OAc)2 (.221g, .32mmol, 0.5eqv) was then added under argon gas. Solution was left to stir overnight. At the beginning of stirring, the solution was a pale yellow color. Began stirring at 9:15am.

2/21/17- Ring Closing of the MonoMethyl work up

Stirring was turned off after 119 hours. Reaction progress was checked to assess completion. Silica gel plate. 50/50 etoac/hexane, UV active. See TLC

Silica Gel Plate

S=starting material

Phi= Phi(OAc)2

Closed=closed ring product

Co= CoSpot

Active under UV light. 



Attached Files
21st February 2017 @ 14:31

Reaction run on 1/26/17



4-(difluoromethoxy) benzaldehyde (1.5mL) was added to the 2-chloro-6-hydrazineyl-3,5-dimethylpyrazine (0.8g) produced in the last reaction. Ethanol (20mL) was also added with vigorous stirring. The product will be left to stir under an argon atmosphere overnight and TLC will be used to monitor the completeness of the reaction.


Table of Reagents (Addition of DifluoromethoxyBenzaldehyde)

     

Reagent

mass (g)

mols

Molecular Weight (g/mol)

Volume (mL)

Density (g/mL)

Product Monomethyl after Hydrazine Rxn

0.4000

0.0025

158.59

   

Difluoromethoxy benzaldehyde

1.9530

0.0075

172.1300

1.0

1.3020

Ethanol

11.08

0.3427

46.0690

15.0

0.7893

Product Dimethyl Benzaldehyde Rxn

0.2000

0.00064

312.70

   
   

Percent Yield

 

Actual Yield: 1

0.2

26%

*When I first weighed this product after the reaction the yield was 127%. The mass must have come from the solvent.

     

 

 

 

 
Attachments Below: 
1. Silica gel plate, 50/50 etoac/hexane, UV active.
2. NMR attached
 
Attached Files
10th December 2016 @ 06:27
New: new

Synthesis of ClC1=CN=C(C)C(NN)=N1

Reaction was run on 12/7

 

Table of Reagents (Monomethyl CsF)

 
 
 
 
 

Reagent

mass (g)

mols

Molecular Weight (g/mol)

Volume (mL)

Density (g/mL)

3,5-dichloro-2-methylpyrazine

0.5000

0.0031

161.9800

0.5000

 

Hydrazine

0.0989

0.0031

32.0460

0.0970

1.0200

Cesium Fluoride

1.4067

0.0093

151.9000

0.3414

4.1200

 

3,5-dichloro-2-methylpyrazine (.500g) was dissolved in dimethyl sulfoxide (4.5 mL). Cesium fluoride (1.4g) and hydrazine (0.15mL)  were added and the reaction mixture was stirred overnight.

 

Source: http://pubs.acs.org/doi/pdf/10.1021/ol4006695