Reacción #707919

Ecuación de reacción

6-aminohexanoic acid methylester hydrochloride

N-methylmorpholine

Boc-(D)-alanine

isobutylchloroformate

→

Boc-(D)Ala-NH(CH2)5CO2Me

Disolventes

methylene chloride

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato warm slowly to 20° before it
2. 2
   Temperaturawas again cooled to -78° C.
3. 3
   TemperaturaFollowing warming this mixture to room temperature
4. 4
   FiltraciónPrecipitated N-methylmorpholine hydrochloride was filtered off
5. 5
   workup.ADDITIONthe filtrate, after diluting with CH2Cl2 (200 ml)
6. 6
   Lavadowas washed 3×100 ml of 0.5N potassium bisulfate (KHSO4)
7. 7
   ExtracciónThe combined aqueous washes were extracted with a 100 ml portion of CH2Cl2
8. 8
   Lavadothe combined organics were washed 1×75 ml of brine
9. 9
   Secadodried over Na2SO4 (anhy.)
10. 10
    Otroused in subsequent reactions without further purification
11. 11
    OtroOptical rotation [α]D +21.5° and +93.7° (365 nm) CHCl3

Procedimiento

Boc-(D)-alanine (5.1 g, 26.9 mmol) in 100 ml of methylene chloride (CH2Cl2) was cooled to 0° C. and 5.9 ml (53.8 mmol) of N-methylmorpholine (NMM) were added. After cooling this vigorously stirred solution to -78° C., 3.5 ml (26.9 mmol) of isobutylchloroformate (IBCF) were added to this reaction which was run entirely under an Ar atmosphere. The mixture was allowed to warm slowly to 20° before it was again cooled to -78° C. and 4.9 g (26.9 mmol) of 6-aminohexanoic acid methylester hydrochloride were added in a single portion. Following warming this mixture to room temperature, it was allowed to stir 25 hour (h). Precipitated N-methylmorpholine hydrochloride was filtered off and the filtrate, after diluting with CH2Cl2 (200 ml), was washed 3×100 ml of 0.5N potassium bisulfate (KHSO4). The combined aqueous washes were extracted with a 100 ml portion of CH2Cl2 and the combined organics were washed 1×75 ml of brine, dried over Na2SO4 (anhy.), and stripped of all solvent under reduced pressure. By thin layer chromatography (10% ethanol (EtOH)/chloroform (CHCl3)) the yellow liquid title product was essentially one spot and used in subsequent reactions without further purification. Optical rotation [α]D +21.5° and +93.7° (365 nm) CHCl3. NMR shift of the (D)Ala methyl=1.34 δ (CDCl3).

Fuente