| US 7,585,988 B2 | ||
| Salt of (2S, 3S) -3- [[(1S) -1- isobutoxymethyl-3-methylbutyl] carbamoly] oxirane-2-carboxylic acid | ||
| Atsushi Tendo, Saitama (Japan); Toshihiro Takahashi, Saitama (Japan); Tomio Yamakawa, Chiba (Japan); Kazuki Okai, Saitama (Japan); and Susumu Nihashi, Chiba (Japan) | ||
| Assigned to Nippon Chemiphar Co., Ltd., Chiyoda-ku, Tokyo (Japan) | ||
| Appl. No. 10/553,946 PCT Filed Apr. 22, 2004, PCT No. PCT/JP2004/005767 § 371(c)(1), (2), (4) Date Oct. 21, 2005, PCT Pub. No. WO2004/096785, PCT Pub. Date Nov. 11, 2004. |
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| Claims priority of application No. 2003-121103 (JP), filed on Apr. 25, 2003. | ||
| Prior Publication US 2006/0252826 A1, Nov. 09, 2006 | ||
| Int. Cl. C07D 303/48 (2006.01) | ||
| U.S. Cl. 549—549 [549/541] | 5 Claims |
| 1. A process for preparation of crystalline sodium or potassium (2S,3S)-3-[[(1S-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylate,
comprising the following steps (1) to (6):
(1) hydrolyzing an ester of (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylic acid, to obtain
(2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylic acid,
(2) causing the carboxylic acid obtained in the preceding step to react with an organic amine, to prepare a salt of (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylic
acid with the organic amine,
(3) adding an acid to the salt obtained in the preceding step, to obtain (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylic
acid,
(4) causing the carboxylic acid obtained in the preceding step react with a basic sodium or potassium compound in a mixed
solvent of water and an aliphatic alcohol or acetone, to obtain a sodium or potassium salt,
(5) recrystallizing the sodium or potassium salt obtained in the preceding step using an aliphatic alcohol, and
(6) drying the product recrystallized in the preceding step under reduced pressure.
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