Réaction #83122

ord-41ed5fb5f01245898410dd7345481174

Conditions de réaction

Conditions détaillées
See reaction.notes.procedure_details.

Traitement

  1. 1
    Lavagewashed with 1M citric acid solution
  2. 2
    SéchageThe dried (MgSO4) organic phase
  3. 3
    Autrewas evaporated to dryness
  4. 4
    Autrechromatographed over silica using 2% MeOH

Mode opératoire

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.

Source

DOI: 10.6084/m9.figshare.5104873.v1Brevet: US05622983uspto-grants-1997_04