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29th September 2013 @ 06:31

 

To a well stirred solution of AEW 86-1 (1.7 g, 5.5 mmol) in CH2Cl2 (11 mL) was added PhI(OAc)2 (1.8 g, 5.5 mmol) and the resulting reaction mixture was stirred at room temperature for 2 h - still SM, but product too - no change after 3 hours so solvent was evaporated under vacuo. The crude residue was purified by flash column chromatography over silica (100% EtOAc - used as the compound was so insoluble) to afford a dark orange solid (493 mg) containing product and and unreacted.

It appears that a large amount of the crude reaction mixture remains at the top of the column, seems quite insoluble and perhaps crystalisation would be a better method for purification, however the gradient was too polar to achieve purification so a second column will be necessary - don't think recrystallisation will work at this stage.

A second column was performed (30-50% EtOAc in Petrol then 100% EtOAc) two fractions collected:

 

For reference, reported synthesis for para-nitrilebenzene compound gave 38% yield from crude (7.6 g SM to 3 g product).

Data:

TLC (30% EtOAc in Hex, 1.5 h)

AEW 87-1 1.5 h (30% EtOAc in Hex).jpg

1H NMR  

Impure NMR:

AEW 87-1 columned but not pure carbon.pdf
AEW 87-1 columned but not pure proton.pdf
AEW 87-1.zip
AEW 87-1 impure.jpg

Hazard and Risk Assessment:

InChi Strings:

InChI=1S/C11H8BrClN4/c12-9-3-1-8(2-4-9)5-15-17-11-7-14-6-10(13)16-11/h1-7H,(H,16,17)/b15-5-

to

InChI=1S/C11H6BrClN4/c12-8-3-1-7(2-4-8)11-16-15-10-6-14-5-9(13)17(10)11/h1-6H

Attached Files
27th September 2013 @ 02:27

Starting Material Synthesis: Synthesis of 2-Chloro-6-hydrazinylpyrazine (AEW 85-1)

Started 11:30am

AEW 86-1 (900 mg, 6.2 mmol) was sirred in AcOH (0.3 mL) in MeCN (9mL) and 4-bromobenzaldehyde (1.15 g, 6.3 mmol) was added to the orange suspension and the resulting reaction mixture stirred at room temperature for ten minutes. Solid mass formed so MeCN (9 mL) was added and the suspension stirred for 30 min. The solvent was removed under vacuo to yield an orange solid (1.93 g, 6.2 mmol, quant. crude yield).

Data:

TLC 30% EtOAc in Hex

AEW 86-1 30%EtOAc in Hex.jpg

1H NMR  

AEW 86-1 crude proton.pdf
AEW 86-1.zip

Proton integrals seem off but going to use material in the next reaction - as Patrick Thomson commented, its E/Z isomers.

2013-10-10 16.14.04.jpg
 

Hazard and Risk Assessment:

HIRAC AEW 86-1.pdf

InChi Strings:

InChI=1S/C4H5ClN4/c5-3-1-7-2-4(8-3)9-6/h1-2H,6H2,(H,8,9) 

and

InChI=1S/C7H5BrO/c8-7-3-1-6(5-9)2-4-7/h1-5H

to

InChI=1S/C11H8BrClN4/c12-9-3-1-8(2-4-9)5-15-17-11-7-14-6-10(13)16-11/h1-7H,(H,16,17)/b15-5-

Attached Files
25th September 2013 @ 04:36

 

Started 21:05

2,6-Dichloropyrazine (1 g, 6.7 mmol) was vigorously stirred in ethanol (10 mL) and hydrazine hydrate (0.33 mL, 340 mg, 6.7 mmol) was added. The resulting mixture was heated at 80 ˚C for 12 h.

After completion (monitored by TLC, 30% EtOAc in Hexane, Rf = 0.2) solvent was removed under vacuo to yield a crude orange solid (940 mg, 6.5 mmol, 97% crude yield).

Data:

TLC 12 h, 30% EtoAc in Hex (doesn't stain very well in vanillin)

AEW 85-1 30%EtOAcinHex.jpg

1H NMR (300 MHz, CDCl3) δ: 8.14 (1H, s), 7.90 (1H, s), 6.37 (1H, s), 3.80 (2H, bs).

AEW 85-1 PROTON.pdf
AEW 85-1.zip

Hazard and Risk Assessment:

HIRAC AEW 85-1.pdf

InChi Strings:

InChI=1S/C4H2Cl2N2/c5-3-1-7-2-4(6)8-3/h1-2H

to

InChI=1S/C4H5ClN4/c5-3-1-7-2-4(8-3)9-6/h1-2H,6H2,(H,8,9)

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Attached Files