[Forsh]

Hi there,
Apologies for the long post,I hope you will bear with me.  I'm trying to protect the phenolic group in 3-aminophenol (I know the title is misleading, but i'll get to that!). 

Background
I decided to go for 2,3-dihydro-3H-pyran a I thought that would be quite selective for the phenolic group.  The mechanism appears to be that the dihydropyran is partially protonated on the C=C double bond, leaving the other carbon slightly positively charged and so susceptible to nucleophilic attack from something like the lone pair on an oxygen.  Obviously an amine also has that lone pair, but I was thinking that it is a much weaker nucleophile and also the reaction occurs under an acid catalyst, so the amine would be protonated and the lone pair no longer free to act as a nucleophile (http://www.organic-chemistry.org/protectivegroups/hydroxyl/thp-ethers.htm).  Am I wrong though?  Would you expect the amine to also react with dihydropyran with an acid catalyst?

Experimental
1 equiv aminophenol and the acid catalyst (0.1 equiv pyridinium p-toluenesulphonate) was dissolved in acetone, before 1.5 equiv hydropyran was added with strong stirring.  This was reacted for 4 hours.  Over the time the colour changed from pale yellow, then stronger yellow, then orange red, then dark green - I don't think this is a good sign. 
I foolishly pumped off the solvent under vacuum and obtained a sticky tar, which redissolved (eventually) in acetone.  I've extracted with several solvents and washed with DI and brine which has given me a few different coloured solvents, reds and yellows.  I'm guessing i've made a few strongly coloured polymers.  The IR is promising, but that could be wishful thinking.  I don't have access to anything better than IR for a few weeks.

IR

Before cleanup


After cleanup


IR of my starting material here (3-aminophenol) I ran an IR of this to begin with, it was the same as this link but I can't find my printout anywhere
http://sdbs.db.aist.go.jp/sdbs/cgi-bin/direct_frame_disp.cgi?sdbsno=1514

[Parisa]

Dear Forsh

I think u made some mistakes in ure experimental.
I don't know if it is possible or not! but I can suggest u some steps:

first you need 1.2 eq DHP against 1 eq 2-aminophenol
then, u should add drop wise aminophenol to DHP which is mixed with cat.
u can study following links:
http://www.orgsyn.org/demo.aspx?prep=cv7p0160
http://www.orgsyn.org/demo.aspx?prep=cv7p0334

Be lucky