https://www.google.com/patents/WO2006002342A1?cl=en
4-Amino-indan-5-carboxylic acid methyl ester
Add 30% aqueous hydrogen peroxide solution (5 mL) in water (44 mL) to a solution of l,6,7,8-Tetrahydro-l-aza-as-indacene-2,3-dione (3.80 mg, 20.3 mmol) and NaOH (5.03 g, 126 mmol) in water (97 mL) over a period of 30 minutes, stir the mixture at room temperature for 1 h. Acidulate with 1 N hydrochloric acid, filter the solid, wash with water and dry to afford 4-amino-indan-5-carboxylic acid (3.13 g, 87%). Dissolve 4- amino-indan-5-carboxylic acid (3.07 g, 17.3 mmol) in ethyl acetate (87 mL) and ethanol (87 mL) and add (trimethylsilyl) diazomethane (17.3 mL, 34.6 mmol, 2 M in hexanes) at room temperature and stir the solution for 1 h. Remove the solvent under reduced pressure. Purify the residue by flash chromatography, eluting with hexanes/ethyl acetate, to afford the title compound (2.50 g, 76%). 1H NMR (MeOD, 300 MHz) δ 2.12 (quintuplet, J = 7.6 Hz, 2H), 2.75 (t, J = 7.5 Hz , 2H), 2.89 (t, / = 7.5 Hz , 2H), 3.83 (s, 3H), 6.53 (d, /= 8.1 Hz, IH), 7.66 (d, J = 8.1 Hz, IH). MS (ES+): 192 (M+H).
