orgchem712
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Bromazolam ranging melting points
Hi,
I have a sample of bromazolam that I have preformed a melting point test on, the results are ranging from 235c - 267c. Literature says the melting
point should be 272c - 275c.
I've been told below that the melting point is not as the literature says because of bromine content.
"The ingredient content of both products is 99%+
But the first 99% product has a high content of bromine in its impurities.
The other impurities in the second 99% single impurity are relatively high.
So the melting points of these two products with the same 99% purity are definitely different."
Can anyone elaborate further, can the sample still be 99%+ and have a ranging melting point from 235c to 267c?
Or ishould the melting point be 272c - 275c sharp?
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Jenks
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Probably not. I don't know what the two products is referring to, but in general, the less pure something is, the broader the melting range will be.
Back when I taught a college qualitative organic analysis class that used old methods, particularly preparing derivatives of an unknown and
identifying them by their melting points, we had a rule that if the melting range was more than three degrees, the derivative was insufficiently pure
and should be recrystallized again.
[Edited on 18-3-2024 by Jenks]
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unionised
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The effect on melting point is proportional to the number of molecules of impurity (The mole fraction if we are being technical).
If you have the same % impurity by weight, but it consists of heavier molecules, there will be fewer molecules and they will have less effect on the
MPt.
Molecules with bromine in them are likely to be heavy simply because bromine atoms are heavy.
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Texium
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That’s a huge melting range. No way is that going to be 99% pure, no matter what the impurities are.
[Edited on 3-18-2024 by Texium]
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orgchem712
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Yes that's what I thought, the seller is bullshiting me about about bromine impurities etc.
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