| 摘要 |
FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method for preparing (3S)-3-amino-3-pyridylpropionic acid or its derivatives of the formula (I) wherein R1 represents pyridyl or substituted pyridyl; R2 represents hydrogen atom, alkyl or aralkyl. Method involves interaction of compound of the formula (II) at pH 7-111 with di-tert. - butylbicarbonate to form compound of the formula (III) wherein R5 represents N-tert. -butoxycarbonyl; interaction of compound of the formula (III) with at least 0.5 equivalent of (1R, 2S)-(-)-ephedrine in alkyl acetate solvent to form salt of the formula (IV) wherein Ph represents phenyl; interaction of salt of the formula (IV) with inorganic base in water to form carboxylate salt of compound of the formula (V) , acidification of carboxylate salt of compound of the formula (V) with acid with value pKa = 3 or less to value pH about 3.5-6.5 to form compound of the formula (V); interaction of compound of the formula (V) with acid with value pKa = 3 or less differing from potassium bisulfate, sodium bisulfate and acetic acid at temperature less about 25 C to form compound of the formula (I) as acid or its conversion if necessary to ester. Proposed method uses available reagents and provides preparing end compounds with good yields and purity. Invention describes intermediate compound of the formula (Va) also. EFFECT: improved preparing method. 26 cl, 22 ex |
