Water → HCID 13772599, compound

Participants

Reaction Steps

While stirring at 0°, 6.4 ml (83.6 mmol) of trifluoroacetic acid (density=1.49) are added to a solution of 1.59 g (3.17 mmol) of N-tert.-butoxycarbonyl-L-alanine-3-[2-(3-benzoylphenyl)-propionylamino]-2-hydroxypropylamide, containing 0.21 mol of water, in 25 ml of absolute methylene chloride and the resulting solution is stirred for 3 hours at 0°. 60 ml of diethyl ether are then added to the clear colourless solution and the resulting suspension is stirred for 15 minutes at 0°. The colourless crystals formed are filtered off with suction and washed with diethyl ether. 1.45 g of crude product are obtained; this is suspended again in 50 ml of hot diethyl ether. After cooling, the suspension is stirred for a further one hour at room temperature and the resulting crystals are filtered off with suction and washed with diethyl ether. L-alanine-3-[2-(3-benzoylphenyl)-propionylamino]-2-hydroxypropylamide trifluoroacetate is obtained in the form of colourless crystals that decompose at 92° and above and contain 0.25 mol of water; [α]D20 =+10.9°±0.9° (c= 1.054; methylene chloride), Rf =0.12 (chloroform:methanol=4:1), Rf =0.17 (chloroform:methanol=7:3), Rf =0.23 (chloroform:methanol:water=70:30:5).

Provenance & Evidence