US 11,746,081 B2
Methods of synthesizing 4-valyloxybutyric acid
Jia-Ning Xiang, Fremont, CA (US); Hao-Wei Shih, New Taipei (TW); Xiaoming Wu, Wuhan (CN); Xuan Zhang, Wuhan (CN); and James Tien, Taoyuan (TW)
Assigned to XWPHARMA LTD., Grand Cayman (KY)
Filed by XWPHARMA LTD., Grand Cayman (KY)
Filed on Feb. 16, 2022, as Appl. No. 17/673,335.
Application 17/673,335 is a continuation of application No. 17/351,550, filed on Jun. 18, 2021, granted, now 11,279,669.
Application 17/351,550 is a continuation of application No. PCT/US2020/066047, filed on Dec. 18, 2020.
Claims priority of application No. PCT/CN2019/127065 (WO), filed on Dec. 20, 2019.
Prior Publication US 2022/0234994 A1, Jul. 28, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C07C 229/08 (2006.01); C07C 227/18 (2006.01); C07C 227/20 (2006.01); C07C 269/06 (2006.01); C07C 271/22 (2006.01); C07C 227/16 (2006.01)
CPC C07C 229/08 (2013.01) [C07C 227/16 (2013.01); C07C 227/18 (2013.01); C07C 227/20 (2013.01); C07C 269/06 (2013.01); C07C 271/22 (2013.01)] 16 Claims
 
1. A method of preparing a compound of Formula (I-D):

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or a pharmaceutically acceptable salt thereof, comprising contacting a compound of Formula (I-H):

OG Complex Work Unit Chemistry
with gaseous hydrogen in the presence of a catalyst and a solvent.
 
6. A method of preparing a compound of Formula (I-H):

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comprising contacting a compound of Formula (I-F):

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with a base, wherein X− is Cl.
 
9. A method of preparing a compound of Formula (I-F):

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comprising contacting a compound of Formula (I-G):

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with hydrochloric acid in the present of a solvent, wherein X− is Cl.
 
11. A method of preparing a compound of Formula (I-A):

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wherein R1 is tert-butoxy carbonyl; and R2 is benzyl, comprising contacting a compound of Formula (I-B):

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with a compound of Formula (I-C):

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in the presence of a base and a solvent, wherein the base is selected from N,N-diisopropylethylamine, triethylamine, potassium carbonate, sodium carbonate, and sodium bicarbonate.