[biofm]

I'm running an esterification of 2-methoxypropanol with an alkyl carboxylic acid using conc. H2SO4 as a the catalyst. The reaction started colorless, then faint yellow upon heating, and finally dark (black or brown) upon refluxing. I'll work up the reaction tomorrow but I can't stop thinking about the dark color. I have done many esterification but have not witnessed very dark colors especially with straight chain alkyl alcohols and carboxylic acids. What could be causing the dark color?

[wildfyr]

Might have chewed things up with too much sulfuric acid. a "drop" or truly small catalytic amount is enough for a small scale reaction.

[biofm]

Could be right. The dark color was just odd.

[Babcock_Hall]

It does not take much material to produce color.  Perhaps only some of your material degraded.