Nitric Acid → 5,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalen-2-amine

A mixture of HNO3 [63%] (0.94 mL) and H2SO4 (1.5 mL) was added to 1,1,4,4-tetramethyl-1,2,3,4-tetrahydro-naphthalene 5 (2.0 g, 10.6 mmol) at −10° C. and the reaction mixture was stirred for 1 h. The reaction mixture was poured into ice:water and the product was extracted with CH2Cl2. The organic layer was washed with NaOH (1N), H2O, brine, dried over MgSO4 to give after solvent evaporation 1,1,4,4-tetramethyl-6-nitro-1,2,3,4-tetrahydro-naphthalene (1.87 g, 76%). ref. Kagechika, H., Kawachi, E., Hashimoto, Y., Shudo, K., Himi T., J. Med. Chem., 31, 2182-2192, 1988. To a stirred solution of 1,1,4,4-tetramethyl-6-nitro-1,2,3,4-tetrahydro-naphthalene (0.593 g, 2.5 mmol) in glacial acetic acid (10 mL) was added iron powder (0.77, 13.8 mmol) over a period of 15 min. The reaction mixture was stirred at 60° C. for 3 hours. The volatiles were evaporated and the resulting oil was partitioned between EtOAc and water. Organics extracts were washed with brine, dried over MgSO4 to obtain 5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-ylamine 6 (0.232 g, 46% yield) as a brown solid.

1. additionThe reaction mixture was poured into ice
2. extractionwater and the product was extracted with CH2Cl2
3. washThe organic layer was washed with NaOH (1N), H2O, brine
4. dry with materialdried over MgSO4
5. customto give
6. customafter solvent evaporation 1,1,4,4-tetramethyl-6-nitro-1,2,3,4-tetrahydro-naphthalene (1.87 g, 76%)
7. stirringThe reaction mixture was stirred at 60° C. for 3 hours
8. customThe volatiles were evaporated
9. customthe resulting oil was partitioned between EtOAc and water
10. washOrganics extracts were washed with brine
11. dry with materialdried over MgSO4

ORD record

ord-e32657566e9448a48f1c754ac87ace26

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07923579B2