反应 #1350597

反应方程式

N-methylmorpholine

L-alanine methyl ester hydrochloride

HOBt

Boc-(D)-Methionine

→

Boc-(D)-Met-(L)-Ala-OMe

收率 77.1%

溶剂

DMF

反应条件

后处理

1. 1
   其他Solvent was removed by evaporation
2. 2
   其他the residue was partitioned between dichloromethane (100 ml) and 5% aqueous acetic acid (5 ml)
3. 3
   其他crystallised
4. 4
   其他was removed by filtration
5. 5
   其他the organic layer was separated
6. 6
   洗涤washed with aqueous sodium bicarbonate
7. 7
   干燥dried (MgSO4)
8. 8
   其他evaporated
9. 9
   其他The residue (8.5 g) was purified by flash chromatography in a sinter funnel
10. 10
    洗涤eluting with a mixture of dichloromethane and ether (0% to 100% ether)
11. 11
    workup.ADDITIONThe fractions containing product
12. 12
    其他evaporated

实验过程

N-methylmorpholine (5.6 g), L-alanine methyl ester hydrochloride (3.9 g), HOBt (4.6 g) and 1-(3-dimethlylaminopropyl)-3-ethylcarbodiimide (5.3 g) was added to a solution of Boc-(D)-Methionine (7 g, 0.028 mol) in dry DMF (50 ml). The mixture was stirred overnight. Solvent was removed by evaporation and the residue was partitioned between dichloromethane (100 ml) and 5% aqueous acetic acid (5 ml). On standing HOBt crystallised and was removed by filtration, and the organic layer was separated and washed with aqueous sodium bicarbonate, dried (MgSO4) and evaporated. The residue (8.5 g) was purified by flash chromatography in a sinter funnel eluting with a mixture of dichloromethane and ether (0% to 100% ether). The fractions containing product were combined and evaporated to give Boc-(D)-Met-(L)-Ala-OMe (7.2 g) as a gum which crystallised on standing; NMR (CDCl3): 1.4 (d, 3H), 1.45 (s, 9H), 1.95 (m, 1H), 2.1 (s, 3H), 2.1 (m, 1H), 2.6 (m, 2H), 3.75 (s, 3H), 4.3 (bs, 1H), 4.6 (m, 1H), 5.3 (m, 1H), 6.9 (bs, 1H).

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