Cesium carbonate → HCID 20806458, compound

Participants

Reaction Steps

A mixture of N-Boc-L-tyrosine methyl ester (11.95 g, 40.57 mmol), 3,5-dichloro-4-bromethyl pyridine (see International Patent Application No. PCT/GB99/00589; 10.74 g, 44.56 mmol) and caesium carbonate (14.52 g, 44.56 mmol) in DMF (100 ml) was stirred at room temperature overnight. The solvent was removed in vacuo and the residue partitioned between ethyl acetate and aqueous NaHCO3. The organic layer was washed with citric acid (10%×2), aqueous NaHCO3 (×2) and brine, dried (MgSO4) and concentrated in vacuo to give the title compound as a brown solid (18.0 g, 98%). δH (d6 DMSO) 8.72 (2H, s), 7.25 (1H, d, J 8.2 Hz), 7.19 (2H, d, 18.5 Hz), 6.97 (2H, d, 18.5 Hz), 5.20 (2H, s), 4.13 (1H, m), 3.61 (3H, s), 2.95 (1H, dd, J 13.7, 5.0 Hz), 2.82 (1H, m), 1.32 (9H, s) m/z (ESI, 60V) 477 (M++H).

Provenance & Evidence