反应详情

2 g (0.0066 mol) of L-alanyl-L-proline ethylamide hydrobromide were suspended in 20 ml of dry tetrahydrofuran, 1.84 ml (0.0145 mol) of N-ethylmorpholine and 0.76 ml (0.0079 mol) of ethyl chloroformate were added and the mixture was stirred at room temperature for 2 hours. The solvent was evaporated off and the residue dissolved in 100 ml of chloroform and washed successively with 2-N hydrochloric acid in brine, brine, saturated sodium bicarbonate solution and brine, dried over magnesium sulphate and evaporated to an oil which soon crystallised. Recrystallisation from chloroform/petrol yielded 0.88 g (47%) of N-ethoxycarbonyl-L-alanyl-L-proline ethylamide of melting point 126°-128° C.; [α]D20 =-117.6° (c=1.02% in methanol).

1. customThe solvent was evaporated off
2. dissolutionthe residue dissolved in 100 ml of chloroform
3. washwashed successively with 2-N hydrochloric acid in brine, brine, saturated sodium bicarbonate solution and brine
4. dry with materialdried over magnesium sulphate
5. customevaporated to an oil which
6. customsoon crystallised
7. customRecrystallisation from chloroform/petrol