Acetic Acid → methyl 5-bromo-2-methyl-3-((tetrahydro-2H-pyran-4-yl)amino)benzoate

HRID 1959281Notes

Reaction equation

HRID 1959281 reaction equation
[NH2:1][C:2]1[C:3]([CH3:13])=[C:4]([CH:9]=[C:10]([Br:12])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].[O:14]1[CH2:19][CH2:18][C:17](=O)[CH2:16][CH2:15]1.C(O)(=O)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C([O-])(O)=O.[Na+]>ClCCCl.O>[Br:12][C:10]1[CH:11]=[C:2]([NH:1][CH:17]2[CH2:18][CH2:19][O:14][CH2:15][CH2:16]2)[C:3]([CH3:13])=[C:4]([CH:9]=1)[C:5]([O:7][CH3:8])=[O:6]

Participants

8

Reactant 5

HCID 176Acetic AcidHCID 121599Tetrahydro-4H-pyran-4-oneHCID 516892Sodium BicarbonateHCID 5049666Sodium triacetoxyborohydrideHCID 24729181Methyl 3-Amino-5-bromo-2-methylbenzoate

Product 1

HCID 70872676methyl 5-bromo-2-methyl-3-((tetrahydro-2H-pyran-4-yl)amino)benzoateYield 88.9%

Reagents, catalysts & solvents 2

HCID 111,2-DichloroethaneSolventHCID 962WaterSolvent

Procedure

To a solution of methyl 3-amino-5-bromo-2-methylbenzoate (3.0 g, 12 mmol) in 1,2-Dichloroethane (48 ml) under nitrogen, was added oxan-4-one (2.3 ml, 25 mmol) followed by acetic acid (4.2 ml, 74 mmol). The reaction mixture was stirred for 5 minutes before the addition of sodium triacetoxyborohydride (7.8 g, 37 mmol). After stirring for 64 hours, deionized water (100 ml) was added and the mixture was neutralized with solid NaHCO3. The phases were separated and the aqueous layer was extracted with EtOAc (4×50 ml). The combined organic extracts were dried over MgSO4, filtered and concentrated in-vacuo. The residue was purified by flash column chromatography (50 g silica, Isolute cartridge, 10-30% EtOAc:Heptanes) to give the title compound (3.5 g 85%) as a white solid. LC-MS 99.8%, 2.18 min (3.5 minute LC-MS method), m/z=327.9, 328.9, 329.9, 330.9; 1H NMR (500 MHz, Chloroform-d) δ ppm 7.24 (d, J=1.73 Hz, 1H) 6.85 (d, J=1.58 Hz, 1H) 4.03 (dt, J=11.82, 3.31 Hz, 2H) 3.88 (s, 3H) 3.66 (br.s., 1H) 3.56 (td, J=11.55, 1.97 Hz, 2H) 3.47-3.55 (m, 1H) 2.24 (s, 3H) 2.06 (d, J=13.56 Hz, 2H) 1.47-1.60 (m, 2H).

Workup

  1. customThe phases were separated
  2. extractionthe aqueous layer was extracted with EtOAc (4×50 ml)
  3. dry with materialThe combined organic extracts were dried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated in-vacuo
  6. customThe residue was purified by flash column chromatography (50 g silica, Isolute cartridge, 10-30% EtOAc:Heptanes)

Sources & evidence

ORD record
ord-3bd9e56323ee4ef58ae54211c309227a
Source dataset
uspto-grants-2013_04
Patent number
US08410088B2

Reaction notes

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