References and Notes
- Vater , W. , Kroneberg , G. , Hoffmeuster , H. , Kaller , H. , Meng , K. , Oberdorf , A. , Plus , W. , Schloβmann , K. and Stoepel , K. 1972 . Arzneim.-Forsch. , 22 : 1
- Fleckenstein , A. , Tritthart , H. J. , Döring , H. J. and Byon , K. Y. 1972 . Arzneim.-Forsch. , 22 : 22
- Fleckenstein , A. and Grün , G. 1972 . Arzneim.-Forsch. , 22 : 334
- Meyer , H. , Bossert , F. , Wehinger , E. , Stoepel , K. and Vater , W. 1981 . Arzneim.-Forsch. , 31 : 407
- Iwanami , M. , Shibanuma , T. , Fujimoto , M. , Kawai , R. , Tamazawa , K. , Takenaka , T. , Takahashi , K. and Murakami , M. 1979 . Chem. Pharm. Bull. , 27 : 1426
- Muto , K. , Kuroda , H. , Kawato , H. , Karasawa , A. , Kubo , K. and Nakamizo , N. 1988 . Arzneim.-Forsch. , 38 : 1662
- The symbols in parentheses indicate the configuration of piperidine C-3 position and dihydropyridine C-4 position, respectively.
- Compound 3 gave two spots on TLC17 (50:50:1 CH2Cl2/EtOAc/Et3N as a developing solvent). The isomer giving a higher Rf spot under this condition was (3R ∗, 4R∗)-isomer and named α-isomer.6 Moreover, it was also reported that the α-isomer preferentially crystallized with good selectivity by fractional crystallization of the hydrochloride of 3 6
- The racemic compound (α)-3 was named benidipine, and its hydrochloride have been manufactured as Coniel® by Kyowa Hakko Kogyo Co., Ltd.
- Hantzsch , A. 1882 . Liebigs Ann. Chem. , 215 : 1
- Details of synthetic study of benidipine hydrochloride will be published elsewhere by T. Ogasa et al.
- Wehinger , E. and Bossert , F. Ger. Patent . 2847237 . 1980 . Chem. Abstr., 1980, 93, 150124.
- Ogawa , T. , Hatayama , K. , Maeda , H. and Kita , Y. 1994 . Chem. Pharm. Bull. , 42 : 1579
- The practical syntheses of the chiral 1,4-dihydropyridine monocarboxylic acid 4 by lipase-catalyzed enantioselective hydrolysis, as the key reactions, were reported in the following literatures: Ebiike H. Terao Y. Achiwa K. Tetrahedron Lett. 1991 32 5805 Hirose, Y., Kariya, K., Sasaki, I., Kurono, Y., Ebiike, H. and Achiwa, K., Tetrahedron Lett., 1992, 33, 7157.
- 2-Benzoyloxyethyltrimethylammonium iodide was sensitive to alkaline to yield benzoic acid and 2-hydroxyethyltrimethylammonium iodide, was investigated by Mamalis and Rydon, as one example of the alkaline cleavage of 2-substituted ethyl ester in the following literature. To our knowledge, the alkaline cleavage of such quaternary ammonium salts has not been mentioned except the example: Mamalis P. Rydon H. N. J. Chem. Soc. 1955 1049
- Compound 11 (R1=H, R2=R3=CH3, X=I) was prepared by a similar manner described in experimental section.
- Silica gel plate is Merck Art 11798 from Merck Co., Ltd. in Germany.