Citric Acid → 4-[(Cyclopropylmethyl)oxy]-1-methylcyclohexanecarboxylic acid

Temperatur

0 °C

Diisopropylamine (15 mL, 105 mmol) in THF (100 mL) was cooled to 0° C. under Ar. n-Butyllithium (38 mL, 95 mmol, 2.5M in hexane) was added dropwise over 10 min. The reaction mixture was left to stir for 15 min at 0° C. A solution of 4-[(cyclopropylmethyl)oxy]cyclohexanecarboxylic acid (D43, 9.47 g, 43.0 mmol) in THF (50 mL) was added and the resulting yellow solution was heated at 50° C. for 2 h. The reaction mixture was cooled to 0° C. and iodomethane (8 mL, 128 mmol) was added dropwise, the reaction was then allowed to warm to rt and left to stir for 3 days. 10% Citric acid (200 mL) was then added and the reaction mixture was concentrated by rotary evaporation. The residual mixture was diluted with H2O and extracted with Et2O (2×). The organics were combined, dried (Na2SO4) and concentrated by rotary evaporation to give a mixture of cis and trans 4-[(cyclopropylmethyl)oxy]-1-methylcyclohexanecarboxylic acid (D44, 10.0 g, 93%) as a brown oil.

1. waitThe reaction mixture was left
2. temperaturethe resulting yellow solution was heated at 50° C. for 2 h
3. temperatureThe reaction mixture was cooled to 0° C.
4. temperatureto warm to rt
5. waitleft
6. stirringto stir for 3 days
7. concentrationthe reaction mixture was concentrated by rotary evaporation
8. additionThe residual mixture was diluted with H2O
9. extractionextracted with Et2O (2×)
10. dry with materialdried (Na2SO4)
11. concentrationconcentrated by rotary evaporation
12. customto give

ORD-Eintrag

ord-d131ba8d2b2f4187b5c1f6cbe9b48dc0

Quelldatensatz

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08299257B2