Carbon Dioxide → 1,2,3,4-Tetrahydro-1-naphthoic acid

A mixture of potassium tert-butoxide (74.13 g, 661 mmol) and N,N,N',N'-tetramethylethylenediamine (6.63M, 78.92 mL, 523 mmol) in 1.7 L of hexane was cooled to below -30° C. under a nitrogen atmosphere and then n-butyl lithium (1.6M, 327 mL, 523 mmol) was added over 15 minutes. The mixture was stirred for 15 minutes and 1,2,3,4-tetrahydronapthalene (7.36M, 85.27 mL, 623 mmol) was added. The mixture was stirred for 6 hours at 0° C. and then for 18 hours at between 0° and 20° C. The mixture was aerated with carbon dioxide for approximately 30 minutes and then approximately 1.2 L of water was added. The aqueous layer was separated, cooled in an ice-water bath and acidified with approximately 185 mL of 12N hydrochloric acid. The mixture was then extracted with ethyl acetate (2×1 L) and the combined ethyl acetate layers were dried (NaSO4). The mixture was filtered and concentrated. The residue was dissolved in 170 mL of formic acid and then the solution was diluted with 340 mL of water to give a crystalline product. The product was isolated by filtration, washed with 40 mL of water and dried. The dry material was dissolved in 0.74 L of ethyl acetate and the solution was washed with 0.5 L of water, dried (Na2SO4) and concentrated to give 1,2,3,4-tetrahydro-1-naphthoic acid (38.68 g, 219.6 mol), m.p. 74.4°-79.2° C.

1. temperaturewas cooled to below -30° C. under a nitrogen atmosphere
2. stirringThe mixture was stirred for 6 hours at 0° C.
3. waitfor 18 hours at between 0° and 20° C
4. customThe aqueous layer was separated
5. temperaturecooled in an ice-water bath
6. extractionThe mixture was then extracted with ethyl acetate (2×1 L)
7. dry with materialthe combined ethyl acetate layers were dried (NaSO4)
8. filtrationThe mixture was filtered
9. concentrationconcentrated
10. dissolutionThe residue was dissolved in 170 mL of formic acid
11. additionthe solution was diluted with 340 mL of water
12. customto give a crystalline product
13. customThe product was isolated by filtration
14. washwashed with 40 mL of water
15. customdried
16. dissolutionThe dry material was dissolved in 0.74 L of ethyl acetate
17. washthe solution was washed with 0.5 L of water
18. dry with materialdried (Na2SO4)
19. concentrationconcentrated

ORD record

ord-ea1391b737c04045a7212b611db0546e

Source dataset

uspto-grants-1996_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05576434