Hydrochloric Acid → HCID 131712845, compound

Participants

Reaction Conditions

Reaction Steps

2.74 g (4.8 mmoles) Boc-Tyr-ala-Phe-Gly-NH-NH2 (10) are dissolved in 50 ml anhydrous dimethylformamide and cooled at -30° C. 2.0 ml (12 mmoles) 6 N hydrogen chloride in anhydrous tetrahydrofuran and 0.63 ml (5.28 mmoles) n-butyl nitrite are successively added and the reaction mixture is stirred for 30 min. at -30° C. 1.34 ml (12 mmoles) N-methyl-morpholine are added at -40° C., followed by a precooled (-40° C.) solution of 0.865 g (4.0 mmoles) H-Tyr-NH2.HCl (K. Blau and S. G. Waley, Biochem. J., 57, 538, 1954) and 0.456 ml (4.0 mmoles) N-methylmorpholine in 50 ml dimethylformamide. The reaction mixture is allowed to react for 7 days at -10° C., then it is concentrated to small volume, filtered from salt, and the product precipitated by dilution with chloroform. By crystallization from methyl alcohol-chloroform, 2.0 g of (14) are obtained, m.p. 127°-129° C.; [α]D25 +19.9° (C=1, MeOH); RfA =0.15, RfB =0.56.

Provenance & Evidence