Lithium hydroxide, monohydrate → 5-[(tert-butoxy)carbonyl]-1H,4H,5H,6H,7H-pyrazolo[4,3-c]pyridine-3-carboxylic acid

HRID 2064668Notes

Reaction equation

HRID 2064668 reaction equation
C([O:3][C:4]([C:6]1[C:10]2[CH2:11][N:12]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:13][CH2:14][C:9]=2[NH:8][N:7]=1)=[O:5])C.O.[OH-].[Li+].S([O-])(O)(=O)=O.[K+]>CO.O>[C:18]([O:17][C:15]([N:12]1[CH2:13][CH2:14][C:9]2[NH:8][N:7]=[C:6]([C:4]([OH:5])=[O:3])[C:10]=2[CH2:11]1)=[O:16])([CH3:21])([CH3:19])[CH3:20]

Participants

6

Reactant 3

HCID 168937Lithium hydroxide, monohydrateHCID 516920Potassium bisulfateHCID 252207545-tert-butyl 3-ethyl 1H,4H,5H,6H,7H-pyrazolo[4,3-c]pyridine-3,5-dicarboxylate

Product 1

HCID 509864325-[(tert-butoxy)carbonyl]-1H,4H,5H,6H,7H-pyrazolo[4,3-c]pyridine-3-carboxylic acidYield 96.1%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

A solution of 1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridine-3,5-dicarboxylic acid 5-tert-butyl ester 3-ethyl ester [5.105 g, Reference Example 18(d)] and lithium hydroxide monohydrate (0.870 g) in methanol (30 ml) and water (10 ml) was stirred at 55° C. for 2.5 hours. The mixture was acidified with saturated aqueous potassium hydrogen sulfate solution and extracted three times with ethyl acetate. The organic extracts were combined, dried over magnesium sulfate and concentrated in vacuo to yield 1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridine-3,5-dicarboxylic acid 5-tert-butyl ester (4.442 g) as a pale yellow solid. MS: 268 (M+H)+. HPLC (METHOD G): RT=2.86 minutes.

Workup

  1. extractionextracted three times with ethyl acetate
  2. dry with materialdried over magnesium sulfate
  3. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-9f4996e8c9e84f409c2ee5fa10160e17
Source dataset
uspto-grants-2012_10
Patent number
US08288425B2

Reaction notes

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