Sodium Hydroxide → HCID 10204543, compound

Participants

Reaction Steps

A stirred solution of (2-o-tolylamino-benzoxazol-6-yl)-acetic acid (0.64 g, Reference Example 2) in dimethylformamide (5 mL) was treated successively with diisopropylethylamine (0.59 g), O-7-azabenzotriazol-1-yl)-1,1,3,3,-tetramethyluronium hexafluorophosphate (0.95 g), and a solution of ethyl (5-amino-indan-2-yl)-acetate [0.5 g, Reference Example 8(a)] in dimethylformamide (2.5 mL). After stirring at room temperature overnight the reaction was evaporated and the residual oil was dissolved in ethyl acetate. The ethyl acetate solution was washed twice with dilute hydrochloric acid, then with aqueous sodium bicarbonate, then with water and then evaporated. The residue was dissolved in industrial methylated spirits (100 mL) and the solution was treated with 3 equivalents of aqueous sodium hydroxide. After stirring at room temperature overnight (HPLC showed that none of the intermediate ester remained) the reaction mixture was evaporated. The residue was partitioned between ethyl acetate and water (with the pH of the aqueous layer adjusted to 2 by addition of dilute hydrochloric acid). The organic phase was dried over magnesium sulfate then evaporated. The residual brown gum was recrystallised from a mixture of acetonitrile and water at pH 2, then from acetonitrile after treatment with charcoal to give the title compound (0.050 g). LC-MS: RT=3.21 minutes (100% by ELSD); MS(ES+) 456(MH+).

Provenance & Evidence