Aluminium lithium hydride → HCID 69624833, compound

Temperature

-10 °C

In a dry two-necked flask equipped with dropping funnel and thermometer was added 3(R)-[(2S,5R)-2,5-dihydro-3,6-dimethoxy-5-(1-methylethyl)-2-pyrazinyl]-3-(4-methoxyphenyl)propanoic acid methyl ester (17.5 g, 46.48 mmol) and 559 mL of dry THF. The solution was then cooled to −10° C. in an acetone-ice bath under argon. To the solution was added dropwise a solution of lithium aluminum hydride in THF (0.8 M, 60 mL, 48 mmol) at a rate so as to maintain the internal temperature below 0° C. After the addition, the ice bath was removed, and reaction mixture was stirred at room temperature for 2 hours. The reaction was quenched by the addition of 10 mL of ethyl acetate followed by 25 mL of saturated sodium sulfate solution. The resulting white precipitate was filtered and was washed with ethyl acetate (4×100 mL). The combined filtrate was then concentrated to give 3(R)-[(2S,5R)-2,5-dihydro-3,6-dimethoxy-5-(1-methylethyl)-2-pyrazinyl]-3-(4-methoxyphenyl)propanol, as a colorless oil (17.7 g). TLC (Rf: 0.5, ethyl acetate/hexane=1:1) single spot.

1. customIn a dry two-necked flask equipped
2. temperatureto maintain the internal temperature below 0° C
3. additionAfter the addition
4. customthe ice bath was removed
5. customreaction mixture
6. customThe reaction was quenched by the addition of 10 mL of ethyl acetate
7. filtrationThe resulting white precipitate was filtered
8. washwas washed with ethyl acetate (4×100 mL)
9. concentrationThe combined filtrate was then concentrated

ORD record

ord-eaad6519576a411080a24e670170d089

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06265572B1