Ethylenediamine → HCID 70926668, compound

Participants

Reaction Conditions

Reaction Steps

1,1,2,3,3-Pentamethyl-2,3,6,7-tetrahydro-1H-indene-4,5-dione is first prepared with 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF) via oxidation with (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl (TEMPO) (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-2,3,6,7-tetrahydro-1H-indene-4,5-dione (10 g, 0.04 mol), ethylene diamine (NH2CH2CH2NH2) (2.5 g, 0.04 mol), and diglyme (50 mL). The reaction mixture is heated to 130° C. and stirred for 24 hours. The reaction mixture is then cooled to 25° C. and further oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (10 g, 0.045 mol) for another 8 hours. The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Diglyme is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product 7,7,8,9,9-pentamethyl-5,7,8,9-tetrahydro-6H-cyclopenta[f]quinoxaline (˜10 g) is obtained.

Provenance & Evidence