isopropanol, ethanol failed to react at position five of 5-bromo-2,3-disubsttiued pyrazine at position 2, there is ethanolamine and at position 3, there is chlorine atom .
does it relay to orientation of isopropanol and ethanol?! or acidity impact in SNAr mechanism ?!
Thanks
The pyrazine is deactivated by the amino substituent, and an SnAr reaction just isn't going to happen. With a BOC-protected amino group, and a stronger base (t-butoxide) you might see a benzyne-type of mechanism, with a mixture of 5- and 6-alkoxy products.
You might have more luck acetylating the 5-position, then doing a Baeyer–Villiger oxidation.
Can you write the IUPAC name of your starting material or sketch a drawing for it? what conditions did you use?
for ethanol
The compound (16a) 2-((5-bromo-3-chloropyrazin-2-yl)amino)ethanol (0.100 g, 0.396 mmol) was dissolved in ethanol (CH3CH2OH) (10 ml, 171.2 mmol) with sodium (0.0109 g, 0.473 mmol) and sodium hydride (0.0052 g, 0. 216 mmol) in (50 ml) rbf. The reaction was heated for 24 hours
for isopropanol
The compound (16a) 2-((5-bromo-3-chloropyrazin-2-yl)amino)ethanol (0.100 g, 0.396 mmol) was dissolved in isopropanol (CH3CH2OHCH3) (10 ml, 130.6 mmol) with sodium (0.0109 g, 0.473 mmol) and sodium hydride (0.0052 g, 0.216 mmol) in (50 ml) rbf. The reaction was heated under reflux for 24 hours
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