# Reaction of chloroform, resorcinol and strong base

A common reaction used to identify resorcinol (benzene-1,3-diol) in the laboratory is to react it with chloroform in presence of 30% sodium hydroxide (NaOH). A red coloured solution (or precipitate) is produced. I have searched many books and websites, but none of them give any clue about the actual reaction, its products, far less the reaction mechanism.

The reaction is as follows:

$$\ce{Resorcinol + Chloroform + 30\% NaOH -> Red Colour}$$

So any ideas about what reaction is taking place?