Hydrochloric Acid → HCID 20155177, compound

Participants

Reaction Conditions

Reaction Steps

19.1 g. 1-Aza-spiro(4,5)decan-2-one (prepared as described in J. Org. Chem., 22, 832) are boiled for 90 hours in 190 ml. concentrated hydrochloric acid. After cooling, the reaction mixture is filtered and evaporated and the residue is reprecipitated with methanol/diethyl ether. There are obtained 17.5 g. (68% of theory) of the hydrochloride of 3-(1-aminocyclohexyl)-propionic acid; m.p. 183° C. sinters; 188°-192° C. melts with decomposition. 7 g. thereof are mixed with 5.5 g. phosphorous acid and, after melting at 80° C., mixed dropwise with 5.9 ml. phosphorus trichloride. After stirring for 8 hours at 80° C., 43 ml. 6N hydrochloric acid are added thereto, the temperature is increased to 100° C. and stirring continued for a further 8 hours. The yellowish suspension is then filtered hot, the filtrate is evaporated and the residue, a colourless oil, is stirred into 2 liters of acetone. The precipitate obtained is filtered off with suction and washed with acetone and diethyl ether. There are obtained 4.6 g. (43% of theory) of product which are dissolved in a little water. Purification takes place by fractionation on an Amberlite IR-120 column (H+ form). The individual fractions are tested electrophoretically for purity. After combining the pure fractions, the aqueous solution is again evaporated and again precipitated with acetone. There are obtained 2.9 g. (27% of theory) of white crystals; m.p. 143° C. sinters, 155°-158° C. foaming up; Mrel =0.29.

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