Fmoc-Asn(Trt)-OH prevents the possibility of the amide side chain from undergoing dehydration side reactions during activation, especially with carbodiimide reagents. Fmoc-Asn(Trt)-OH dissolves readily in all standard peptide synthesis reagents, while Fmoc-Asn-OH is only somewhat soluble in NMP or DMF. The trityl group is removed with TFA. This reaction is usually complete within 1 hour at room temperature, but is slower when the Asn(Trt) residue in at the N-terminal of the peptide. In these cases, the deprotection reaction should be extended to 2 hours.
