تفاعل #219328

معادلة التفاعل

isobutyl chloroformate

N-Boc cyanoalanine

NaBH4

triethylamine

→

NaBH4

(S)-(2-Cyano-1-hydroxymethyl-ethyl)-carbamic acid tert-butyl ester

المردود 64.0%

المذيبات

THF

water

ظروف التفاعل

المعالجة

1. 1
   ترشيحfiltered through a coarse scintered glass funnel
2. 2
   درجة الحرارةcooled in an ice/water bath
3. 3
   workup.STIRRINGthe resulting mixture was stirred for 2 hours
4. 4
   أخرىThe THF was removed on the rotary evaporator
5. 5
   workup.ADDITIONdiluted with ethyl acetate and water
6. 6
   استخلاصThe organics were extracted twice with aqueous NaHCO3
7. 7
   تجفيفdried over MgSO4
8. 8
   أخرىThe solvent was removed

الإجراء التجريبي

A solution of N-Boc cyanoalanine (2 g, 9.3 mmol) in THF (30 mL) was cooled in an ice/NaCl bath to −10° C. and treated with triethylamine (0.94 g, 9.3 mmol) followed by dropwise addition of isobutyl chloroformate (1.35 g, 9.9 mmol). The reaction mixture was stirred for 4 minutes at −10° C. and filtered through a coarse scintered glass funnel. Meanwhile, in another flask, a solution of NaBH4 (0.71 g, 19 mmol) in water (10 mL) was prepared and cooled in an ice/water bath. The filtered solution of the mixed anhydride was added dropwise to the cold NaBH4 solution and the resulting mixture was stirred for 2 hours. The THF was removed on the rotary evaporator and the reaction was acidified with 5% NaHSO4 solution to pH 3 and diluted with ethyl acetate and water. The organics were extracted twice with aqueous NaHCO3 and dried over MgSO4. The solvent was removed to afford 1.2 g (64%) of (S)-(2-Cyano-1-hydroxymethyl-ethyl)-carbamic acid tert-butyl ester; 1H NMR (CDCl3, 400 MHz) δ 1.45 (s, 9H), 2.09-2.17 (m, 1H), 2.73 (d, 1H, J=6.0), 3.76 (dd, 1H, J1=4.7, J2=10.8), 3.80-3.86 (m, 1H), 3.91-3.99 (m, 1H), 4.98-5.07 (m, 1H).

المصدر