Methyl iodide → 1-Methyl-3-oxo-2-quinoxalin-2-yl-1,2,3,4,6,7-hexahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester

HRID 984887Notes

Reaction equation

HRID 984887 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11]2[NH:14][N:15]([C:18]3[CH:27]=[N:26][C:25]4[C:20](=[CH:21][CH:22]=[CH:23][CH:24]=4)[N:19]=3)[C:16](=[O:17])[C:10]=2[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[H-].[Na+].I[CH3:31]>CN(C)C=O>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11]2[N:14]([CH3:31])[N:15]([C:18]3[CH:27]=[N:26][C:25]4[C:20](=[CH:21][CH:22]=[CH:23][CH:24]=4)[N:19]=3)[C:16](=[O:17])[C:10]=2[CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 697341853-Oxo-2-quinoxalin-2-yl-1,2,3,4,6,7-hexahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester

Product 1

HCID 697341561-Methyl-3-oxo-2-quinoxalin-2-yl-1,2,3,4,6,7-hexahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl esterYield 63%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 3-oxo-2-quinoxalin-2-yl-1,2,3,4,6,7-hexahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester (prepared according to the method of Example 75, Step A, 250 mg, 0.68 mmol) in dimethylformamide (2 mL) at 0° C. with stirring under nitrogen was added sodium hydride (60% dispersion in mineral oil, 41 mg, 1.02 mmol). After 10 min, iodomethane (51 μL, 0.82 mmol) was added. This mixture was allowed to stir at 0° C. for 2 h, quenched by addition of saturated aqueous sodium bicarbonate and extracted with ethyl acetate (4×). The combined organic extracts were dried over sodium sulfate, filtered, evaporated, and purified by flash column chromatography (40% ethyl acetate/hexanes) to give 164 mg (63%) of the title compound of Example 75, Step B as a yellow foam. 1H NMR (CDCl3, 250 MHz) δ 9.71 (s, 1H), 8.15 (dd, 1H), 8.02 (m, 1H), 7.80-7.70 (c, 2H), 4.29 (s, 2H), 4.14 (t, 2H), 3.79 (s, 3H), 2.72-2.67 (c, 2H), 1.50 (s, 9H); MS (APCI) 382 (MH+).

Workup

  1. customat 0° C.
  2. stirringto stir at 0° C. for 2 h
  3. customquenched by addition of saturated aqueous sodium bicarbonate
  4. extractionextracted with ethyl acetate (4×)
  5. dry with materialThe combined organic extracts were dried over sodium sulfate
  6. filtrationfiltered
  7. customevaporated
  8. custompurified by flash column chromatography (40% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-293045e959814181be606f8fa6a20c80
Source dataset
uspto-grants-2005_03
Patent number
US06869943B2

Reaction notes

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