反応 #1350597

反応方程式

N-methylmorpholine

L-alanine methyl ester hydrochloride

HOBt

Boc-(D)-Methionine

→

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

収率 77.1%

溶媒

DMF

反応条件

後処理

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

実験手順

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).

出典