4-Methylmorpholine → N-Boc-O-benzyl tyrosine methylamide

Participants

Reaction Steps

To a solution of N-tertiarybutoxycarbonyl-O-benzyl-L-tyrosine (7.4 g, 20 mM), 1-hydroxybenzotriazole (3 g, 20 mM), methylamine HCl (1.3 g, 20 mM) and N-methylmorpholine (2 g, 20 mM) in CH2Cl2 (20 ml) stired and cooled to 0° was added DCC (4.2 g, 20 mM). After being allowed to stir and warm to room temperature overnight the reaction mixture was filtered and washed with saturated aqueous sodium bicarbonate solution, 3N citric acid and brine. The dried organic extract was then concentrated in vacuo to give N-tertiarybutoxycarbonyl-O-benzyl-L-tyrosine N-methylamide as a solid. Recrystallisation from dichloromethane/hexane gave (4.5 g); m.p. 165°-172°; (Found: C, 68.85; H, 7.43; N, 7.39. C22H28N2O4 requires C, 68.73; H, 7.34; N, 7.29%); δ (CDCl3) 1.40 (9H, s, OC(CH3)3); 2.73 (3H, d, J=5 Hz, CONHCH3); 2.96 (2H, m, CH2Tyr); 4.25 (1H, m, α-CH); 5.03 (2H, s, CH2C6H5); 5.80 (1H, br, CONH); 6.86 (2H, d, J=8 Hz, Tyr); 7.12 (2H, d, J=8 Hz, Tyr); 7.3-7.5 (5H, m, C6H5).

Provenance & Evidence