Isohexylamine → 5-{2-Methoxy-4-[(4-methylpentylamino)methyl]phenoxy}pyrazine-2-carboxamide

HRID 228463Notes

Reaction equation

HRID 228463 reaction equation
[CH:1]([C:3]1[CH:18]=[CH:17][C:6]([O:7][C:8]2[N:9]=[CH:10][C:11]([C:14]([NH2:16])=[O:15])=[N:12][CH:13]=2)=[C:5]([O:19][CH3:20])[CH:4]=1)=O.[CH3:21][CH:22]([CH3:27])[CH2:23][CH2:24][CH2:25][NH2:26].[BH4-].[Na+]>CO>[CH3:20][O:19][C:5]1[CH:4]=[C:3]([CH2:1][NH:26][CH2:25][CH2:24][CH2:23][CH:22]([CH3:27])[CH3:21])[CH:18]=[CH:17][C:6]=1[O:7][C:8]1[N:9]=[CH:10][C:11]([C:14]([NH2:16])=[O:15])=[N:12][CH:13]=1

Participants

5

Reactant 3

HCID 219608IsohexylamineHCID 4311764Sodium borohydrideHCID 597299775-(4-Formyl-2-methoxyphenoxy)pyrazine-2-carboxamide

Product 1

HCID 597300675-{2-Methoxy-4-[(4-methylpentylamino)methyl]phenoxy}pyrazine-2-carboxamideYield 36.5%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Place 5-(4-formyl-2-methoxyphenoxy)pyrazine-2-carboxamide (Example 719, Part A) (0.700 g, 2.56 mmol), 4-methylpentylamine (Example 433, Part A) (0.272 g, 2.69 mmol) and 3 Å molecular sieves in a vial. Add methanol (12.8 mL), cap and stir overnight. Add NaBH4 (0.0969 g, 2.56 mmol) and stir until the sasses stop evolving. Load the reaction mixture directly onto a 25 g ISCO® pre-load column. Dry the column in a vacuum oven at room temperature. Purify by eluting through a 40 g ISCO® column with 5% to 20% (2.0 M NH3 in methanol) in ethyl acetate over 45 minutes. Concentrate the fraction containing the product, then take it up in EtOAc (100 mL). Wash the organic solution with 1.0 N NaOH (2×25 mL), dry it over Na2SO4, filter and concentrate. Dissolve the product in ether:dichloromethane (5:1) (25 mL), add hexanes (20 mL), and then concentrate to about a quarter of the volume. Filter the precipitate to give the title compound (0.335 g, 36.5%): TOF MS ES+ 359.2 (M+H)+, HRMS calcd for C19H27N4O3 359.2083 (M+H)+, found 359.2087, time 0.38 min; HPLC [YMC-Pro pack C-18 (150×4.6 mm, S-5 microm), 0.05% TFA/acetonitrile in 0.05% TFA/water at 1.0 mL/min, 10-20% over 5 min, 20-95% over 18], tR=11.3 min, 100% purity.

Workup

  1. customDry the column in a vacuum oven at room temperature
  2. customPurify
  3. washby eluting through a 40 g ISCO® column with 5% to 20% (2.0 M NH3 in methanol) in ethyl acetate over 45 minutes
  4. concentrationConcentrate the fraction
  5. additioncontaining the product
  6. washWash the organic solution with 1.0 N NaOH (2×25 mL)
  7. dry with materialdry it over Na2SO4
  8. filtrationfilter
  9. concentrationconcentrate
  10. dissolutionDissolve the product in ether:dichloromethane (5:1) (25 mL)
  11. additionadd hexanes (20 mL)
  12. concentrationconcentrate to about a quarter of the volume
  13. filtrationFilter the precipitate

Sources & evidence

ORD record
ord-fd5b574fc02c4947b578246d06915575
Source dataset
uspto-grants-2009_07
Patent number
US07560463B2

Reaction notes

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