Acetyl chloride → Isohexane ethyl acetate

Acetyl chloride (0.51 mL) was added dropwise to a solution of the terminal alkyne of Reference Example 4 (153 mg, 0.514 mmol) in MeOH (4.6 mL), chilled in an ice bath. The reaction mixture was stirred at RT overnight and then evaporated. Boc-Leu-OH—H2O (145 mg, 0.58 mmol) was added and the mixture was coevaporated from DMF, then redissolved in 5 mL DMF, and cooled in an ice bath. DIEA (0.36 mL, 2.1 mmol) was added, followed by HATU (220 mg, 0.578 mmol). After stirring at 0° C. for 15 min, the mixture was stirred at RT for 3 h and then concentrated. The mixture was dissolved in 20 mL EtOAc, washed successively with saturated aqueous NaHCO3 (10 mL) and saturated aqueous NaCl (2×10 mL), dried (Na2SO4), and evaporated to give a yellow-brown oil. Flash chromatography (silica, 1/1 i-hexane-EtOAc) gave title compound (213 mg, quantitative).

1. temperaturechilled in an ice bath
2. customevaporated
3. temperaturecooled in an ice bath
4. stirringAfter stirring at 0° C. for 15 min
5. stirringthe mixture was stirred at RT for 3 h
6. concentrationconcentrated
7. dissolutionThe mixture was dissolved in 20 mL EtOAc
8. washwashed successively with saturated aqueous NaHCO3 (10 mL) and saturated aqueous NaCl (2×10 mL)
9. dry with materialdried (Na2SO4)
10. customevaporated
11. customto give a yellow-brown oil

ORD record

ord-984fd5cdaece4757a76cca4dc273b4d6

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08426421B2