A catalytic amount (0.1 eq or 0.01 eq) usually does the trick. See for example:

http://www.orgsyn.org/demo.aspx?prep=cv7p0093

http://www.orgsyn.org/demo.aspx?prep=v89p0183

Thank you Mr. Mathias, and EDC?

Same for EDC.

means, same eq. ???

yes

Thank you.

Well, if EDC stands for the coupling agent (carbodiimide), you need at least 1 equivalent of it. DMAP can be used in catalytic amount provided that another base (like Et3N) is present in 1-1.2 equivalent.

Good idea will be to read the review recommended by Petr in the first post. Good luck.