Reacción #83122

ord-41ed5fb5f01245898410dd7345481174

Condiciones de reacción

Condiciones detalladas
See reaction.notes.procedure_details.

Tratamiento posterior

  1. 1
    Lavadowashed with 1M citric acid solution
  2. 2
    SecadoThe dried (MgSO4) organic phase
  3. 3
    Otrowas evaporated to dryness
  4. 4
    Otrochromatographed over silica using 2% MeOH

Procedimiento

A solution of the α-methyl-D-tryptophyl-L-phenylalaninol (0.5 g, 1.42 mmol) and 4-N,N-dimethylaminopyridine (0.2 g, 1.64 mmol), in anhydrous THF (20 mL) was treated dropwise with a solution of 2-adamantylchloroformate (1.4 mmol) in anhydrous THF (20 mL) at room temperature. The reaction was monitored by IR spectroscopy. Once complete, the reaction mixture was diluted with ethyl acetate and washed with 1M citric acid solution, then water. The dried (MgSO4) organic phase was evaporated to dryness and chromatographed over silica using 2% MeOH:98% CH2Cl2 as eluant. This gave the required compound (65% along with 20% carbonate impurity. NOTE: Some of the more acid labile urethanes required chromatography on neutral stationary phases. mp 96°-100° C. (EtOAc-hexane); IR (KBr) 3316, 1695 and 1658 cm-1 ; NMR (CD3OD) δ1.28 (3H, s), 1.55 (2H, m), 1.68-2.06 (12H, m), 2.76 (2H, ABx, J 13.5 and 17Hz), 3.31 (2H, Abq, J 14.5Hz), 3.45 (2H, m), 4.12 (1H, m), 4.78 (1H, br.s) and 6.8-7.5 (10H, m); Anal (C32H39N3O4), C, H, N.

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US05622983uspto-grants-1997_04