(S)-2-((tert-Butoxycarbonyl)amino)-3-cyclopropylpropanoic acid → (S)-tert-Butyl 1-cyclopropyl-3-hydroxypropan-2-ylcarbamate

To a solution of (2S)-2-[(tert-butoxycarbonyl)amino]-3-cyclopropylpropanoic acid (2.5 g, 11 mmol) in tetrahydrofuran (30 mL) at 0° C. was added 1.0 M borane-THF complex in THF (32.4 mL). After addition, the reaction mixture was stirred at room temperature for 3 hours, then cooled down with an ice-bath, quenched by the slow addition of AcOH:MeOH (1:5, 20 mL) and the mixture was then warmed to room temperature for 2 hours. The THF volume was reduced by ½ and the product was partitioned between saturated aqueous NaHCO3 and DCM. The combined organic fractions were dried over Na2SO4 and concentrated under reduced pressure to give an oil residue, which was used directly in the next reaction without further purification. LC-MS found: 216.1 (M+H)+.

1. additionAfter addition
2. temperaturecooled down with an ice-bath
3. customquenched by the slow addition of AcOH:MeOH (1:5, 20 mL)
4. temperaturethe mixture was then warmed to room temperature for 2 hours
5. customthe product was partitioned between saturated aqueous NaHCO3 and DCM
6. dry with materialThe combined organic fractions were dried over Na2SO4
7. concentrationconcentrated under reduced pressure
8. customto give an oil residue, which
9. customwas used directly in the next reaction without further purification

ORD-Eintrag

ord-8260b58114fa4f20be81c01867bbcf7f

Quelldatensatz

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08895571B2