The reaction of removing the Fmoc from the α-amino
group of the amino acid was performed with 25% piperidine
in DMF for 5 and 15 min. After deprotection a longer
cycle of washes was performed, according to the scheme:
DMF, DCM : DMF, DCM, DMF, DCM : DMF, DCM, repeated
every 3 × 2 min.