Methyl iodide → Methyl 2-(4-t-butylphenyl)propanoate

A solution of methyl-2-(4-tert-butylphenyl)acetate (1 g, 4.85 mmol) in abs. THF (30 ml) was mixed with a 1 M solution of bis-(trimethylsilyl)lithium amide in THF (5.33 ml, 5.33 mmol) at a temperature of −70° C. within 15 min. The reaction was highly exothermic. The mixture was kept for 20 min at −70° C. and at this temperature methyliodide (0.452 ml, 1.03 g, 7.26 mmol) was added within 5 min. Within 16 h the mixture was heated to RT. For working up, the reaction mixture was mixed with sat. NH4Cl solution (30 ml). There were formed two phases and, as a solid, ammonium chloride which was separated off by filtration and washing with THF (2×8 ml). The filtrate was mixed with DCM (70 ml) and the phases were separated. The aqueous phase was extracted with DCM (2×20 ml). The organic phases were combined, dried and concentrated. There remained a colourless oil (1.08 g) which was purified by chromatography [silica gel 60 (50 g); cyclohexane (800 ml), EtOAc/cyclohexane 1:30 (600 ml)]. 2-(4-Tert-butylphenyl)propionic acid methyl ester was obtained as a colourless oil in a yield of 89% (946 mg).

1. additionwas added within 5 min
2. customThere were formed two phases
3. customas a solid, ammonium chloride which was separated off by filtration
4. washwashing with THF (2×8 ml)
5. additionThe filtrate was mixed with DCM (70 ml)
6. customthe phases were separated
7. extractionThe aqueous phase was extracted with DCM (2×20 ml)
8. customdried
9. concentrationconcentrated
10. customwas purified by chromatography [silica gel 60 (50 g); cyclohexane (800 ml), EtOAc/cyclohexane 1:30 (600 ml)]

ORD record

ord-52881ba2f0e94fd59758b31f3e68dd87

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08772307B2