Oxytocin, a nonapeptide amide, was synthesized on a benzhydryl-resin using the Boc strategy. Benzyl group was
used in the protection of sulfhydryl group of cysteine and tyrosine side-chain. Benzhydryl and tetralinyl groups were
used in the protection of glutamine and asparagine side-chains respectively. TFMSA-TFA-thioanisole-I,2-
ethanedithiol (2:20:2:1 v/v) was used on the peptide-resin under different cleavage conditions to obtain oxytocin in a
one-pot reaction. The cleavage at 40°C for two hours gave oxytocin quantitatively. Oxytocin could be isolated in
56% yield.