[Champenois]

Need some help in the following, if I'm not in the right forum please assist..

Wikipedia defines the chemical name for Lufenuron (chitin inhibiting pesticide for Vet use - flea control dogs etc) as:
1-[2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea
(http://en.wikipedia.org/wiki/Lufenuron) with the following as other names:
N-[ [ [2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]amino]carbonyl]-2,6-difluorobenzamide
Fluphenacur

I have been given some "Lufenuron" with the following chemical name:
1-[2,5-dichloro-3-(1,1,2,3,3,3-hexafluoro propoxy)phenyl-3-(2,6-dichloro benzoyl )]urea

Can anyone tell me the difference and if it's going to kill the dogs? Sorry, for the big request but I've got to start somewhere without the expense of lab testing (and the huge expense of buying store-bought Lufenuron).

[Archer]

Need some help in the following, if I'm not in the right forum please assist..

1-[2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea

1-[2,5-dichloro-3-(1,1,2,3,3,3-hexafluoro propoxy)phenyl-3-(2,6-dichloro benzoyl )]urea

I couldn't say whether it's going to harm an animal or not, your difference, as far as I can see, is that the two fluoride atoms have been replaced with chlorides. This will change the pharmacology to a certain extent. They also seem to be positional isomers.

If you are unsure then I would not use it.

[Dan]

Beaten to it...

Structures:

                                                                           
                                             difference               difference
                                                                           



Might be worth checking with the supplier that it is not a typographical error on the label since the chemical name they've given does not match common/trade name.

[Archer]

The perfluoropropoxy group is in the 3 position in the second one but in the 4 position in the first one.

[Archer]

Sorry, hexafluoropropoxy group, not perfluoro.

[Champenois]

tks for the help everyone, I'll email and ask the supplier tonight

[Babcock_Hall]

Dan, Do you think it is possible that one compound represents a later variant of the other?  Meaning that when one drug became ineffective, the manufacturer replaced it with a closely related compound?

[Champenois]

I've heard back from my supplier regarding the change in chemical name.

They say that the Wikipedia name for Lufenuron (as as first presented to me at enquiry time):
1-[2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea
is the sample they sent me, and that the purity lab test sheet (where the second name is stated - 1-[2,5-dichloro-3-(1,1,2,3,3,3-hexafluoro propoxy)phenyl-3-(2,6-dichloro benzoyl )]urea).. is "only" a purity test and not for Lufenuron. Yes, a fairly standard reply for this particular country.

Accordingly, it's impossible for me to know now with certainty whether I've got (access to) real Vet grade Lufenuron or not.

The only other indicator is that it's $400 per kilo which is the going rate from this source country (China) for non-agricultural Vet. grade.. yes, that can't be relied on in any way.

Can anyone tell me how practical and expensive it is to determine the compositional accuracy against the Lufenuron formula - C17H8Cl2F8N2O3 ?

Thank you for the help..

[Dan]

Dan, Do you think it is possible that one compound represents a later variant of the other?  Meaning that when one drug became ineffective, the manufacturer replaced it with a closely related compound?

I would have thought the name would be changed - why market a new drug under the same name as an obselete drug?

They say that the Wikipedia name for Lufenuron (as as first presented to me at enquiry time):
1-[2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea
is the sample they sent me, and that the purity lab test sheet (where the second name is stated - 1-[2,5-dichloro-3-(1,1,2,3,3,3-hexafluoro propoxy)phenyl-3-(2,6-dichloro benzoyl )]urea).. is "only" a purity test and not for Lufenuron.

This sounds odd. I'm not sure I understand what is meant by that - so they are saying it's Lufenuron in the bottle but with the certificate of analysis (CoA) for a different product?

I take it they did not go for the professional approach and apologise for the mistake and send you the CoA for Lufenuron?

I would be tempted to get in touch with a university chemistry department - most have mass spectrometry services, mass spec will give you an answer. That is probably the cheapest way to check.

[Champenois]

>>I would have thought the name would be changed - why market a new drug under the same name as an obselete drug?

Generally in China inexplicable product differences relate to cost; savings/substitution

>>This sounds odd. I'm not sure I understand what is meant by that - so they are saying it's Lufenuron in the bottle but with the certificate of analysis (CoA) for a different product?

Yes, that's what it seems, quote "about the structure, sample what we sent is lufenuron, in the test report, it should be impurity formula(not lufenuron)"

>>I take it they did not go for the professional approach and apologise for the mistake and send you the CoA for Lufenuron?

, In China if you can slide by without an apology you save face and complexity both at the same time. I don't like it but that's how it is.

>>I would be tempted to get in touch with a university chemistry department - most have mass spectrometry services, mass spec will give you an answer. That is probably the cheapest way to check.

Ok, I'll investigate that, and thanks for all the help, the explanations got me to understand what's real Lufenuron and what's not, I just have to see which one my sample is.

Oh, and they let slip (if true) that fudged, uncertified COA's are because no Chinese Lufenuron factory has passed a "GMP audit", (apparently commences EU 11Jul2013)

Excuse, can't figure out the quoting!

[Archer]

I would gladly test it for you free of charge (always interested in collecting MS data for new substances) but I am not in the US so carriage costs would be very expensive.

[Champenois]

Tks a lot, that sounds interesting, where are you located Archer?

[Archer]

I am in the UK, PM for more details.

[Champenois]

PM sent