[tallec01]

Quickest route to 5-amino-1-naphthol anyone?

[Dan]

It's commercially available, buying it would be the easiest option.

[tallec01]

Fully aware...just curious about the chemistry used to make it. Some sort of condensation involved?

[camptzak]

whats available as starting materials?

[tallec01]

Lets say 1-naphthol or 1-naphthylamine. How would you introduce the other functionality at the 5 position?

[camptzak]

ok well if you were to start with 1-napthylamine you could chlorinate the rings with iron chloride and chlorine gas and then use nucleophilic aromatic substitution to replace the chlorine with a hydroxyl group.
The amine is an activating substituent so you would get chlorine at the 5 position on some rings and at other positions at other rings. So you would have to seperate your desired compounds before hitting it with sodium hydroxide.

If you were to start with 1-napthol you could use sulfuric acid and nitric acid to nitrate the ring. the hydroxyl group is also activating so again you would get nitration at the 5 position as well as other positions and you would have to sperate your desired compound.
you would then have to reduce your nitrated ring to get your amine.

If you are actualy planning on carrying this out then try to start with the amine and add the OH group. That would be the easiest way. I would not actually attempt the nitration pathway.

[orgopete]

If you nitrate 1- or 2-naphol, what is the product? Isn't this a general result from all activating groups? What is the product for the dinitration of naphthalene?

[camptzak]

doesnt the ring undergo addition by the nitrates? at the positions that are allowded by the activating oH?

[AWK]

synthesis
Yakugaku Zasshi. 1976 Oct;96(10):1259-64

[orgopete]

doesnt the ring undergo addition by the nitrates? at the positions that are allowded by the activating oH?

Correct. If you start with 1-naphthol, you will get a mixture of 2-, 4-nitro, and 2,4-dinitro-1-naphthol because the OH is activating. Nitration occurs in the ring containing an activating group.

If you start with 1-nitronaphthalene, nitration occurs in the not deactivated ring and you will get 1,5- and 1,8-dinitronaphthalene. If you start with the naphthalenium salt (C₁₀H₇NH₃⁺) of 1-aminonaphthalene, what product would you predict? (I am thinking hypothetically as I am uncertain of the effectiveness of a naphthalenium salt as a meta director. Anilinium salts may still give some o/p products, as I recall.)

AWK, the reference would be good if I had access to it, but in my case, it will take a week or so to order from the interlibrary loan.

[AWK]

AWK, the reference would be good if I had access to it, but in my case, it will take a week or so to order from the interlibrary loan.

It concerns of synthesis through 1,5-dinitro derivative. After selective reduction (with sulfides) they use Fremy's salt - diazotization removes NH2 completely!).
Nitration of 1-naphtylamine gives mixture 1,5 and 1,8 isomers.

[camptzak]

well im sorry for the bad advice then!
I drew it out and found that when i attacked the ring with the NO₂ at the 5 position I resonated the charge and found the cation under the OH. I must have drawn it incorrectly, I will go back and do it again.