US 12,006,291 B2
Processes for the preparation of 4,6,7-trifluoro-1H-indole-2-carboxylic acid
Kaicheng Zhu, Belmont, MA (US); Tao Wang, Berkeley Heights, NJ (US); Jiajun Zhang, Cambridge, MA (US); Hui Cao, Belmont, MA (US); Ruichao Shen, Belmont, MA (US); Guoqiang Wang, Belmont, MA (US); George G. Wu, Waltham, MA (US); and Yat Sun Or, Waltham, MA (US)
Assigned to Enanta Pharmaceuticals, Inc., Watertown, MA (US)
Filed by ENANTA PHARMACEUTICALS, INC., Watertown, MA (US)
Filed on Jan. 10, 2023, as Appl. No. 18/095,155.
Claims priority of provisional application 63/307,950, filed on Feb. 8, 2022.
Claims priority of provisional application 63/298,471, filed on Jan. 11, 2022.
Prior Publication US 2023/0234922 A1, Jul. 27, 2023
Int. Cl. C07D 209/42 (2006.01)
CPC C07D 209/42 (2013.01) 7 Claims
 
1. A process for producing Compound (1),

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said process comprising the steps of:
(i) reacting Compound (a) with a bromination agent, to produce Compound (b):

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(ii) reacting Compound (b) with N,O-dimethylhydroxylamine HCl, in the presence of an acid activation agent to produce Compound (c):

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(iii) reducing Compound (c) with a reducing reagent to produce Compound (d):

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(iv) reacting Compound (d) with Compound (d-1)

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to produce Compound (e):

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(v) reacting Compound (e) with a hydrogen source, to produce Compound (f):

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and
(vi) hydrolyzing Compound (f) to produce Compound (1):

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