Hydrochloric Acid → N-(indan-2-yl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-2-amine

Participants

Reaction Conditions

Reaction Steps

Add portionwise hydrochloric acid (900 mL; 5M in water; 5.17 equiv; 4.50 mole; 1.08 kg) to a solution of tert-butyl 2-(indan-2-ylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidine-6-carboxylate (319 g; 1.00 equiv; 870.48 mmoles) in tetrahydrofuran (1.5 L). Once the addition is complete, stir the solution at 50° C. for 1 h. Cool the mixture to 25° C. and then add 3 L methyltert-butyl ether and 1 L water. Allow the solution to stand at 20° C. for 16 h. Separate the phases and extract the aqueous phase with dichloromethane (2 L). Discard the organic extracts and adjust the aqueous phase to pH 10 using 4M sodium hydroxide. Extract with ethyl acetate (3×3 L), and wash the combined organic extracts with saturated sodium chloride (2 L). Dry over anhydrous sodium sulfate, filter and concentrate to dryness to give a red gel. Redissolve the substance in ethyl acetate (300 mL) and petroleum ether (200 mL) at 50° C., and allow for precipitation over 24 hours. Filter and dry to afford the title compound (85 g, 37%). MS (m/z): 267 (M+1).

Provenance & Evidence