The esterification of several partially protected peptide fragments through the C-terminal or a free side chain carboxy group with hydroxy groups containing resins and the 2-chlorotritylchloride resin is described. As an application example crude protected Leu 15 - gastrin I ( ) has been obtained in 99% yield by the “solid-phase” method using as the solid support. Crude has been deprotected to free Leu 15 - gastrin ( ) which is thus obtained in 92% yield and 90% purity.
