N-(2-Bromo-5-chloro-pyridin-3-yl)-4-chloro-N-methoxvmethyl-3-trifluoromethyl-benzenesulfonamide → 8-({5-Chloro-3-[(4-chloro-3-trifluoromethyl-benzenesulfonyl)-methoxymethyl-amino]-pyridin-2-yl}-hydroxy-methyl)-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid tert-butyl ester

HRID 1898172Notes

Reaction equation

HRID 1898172 reaction equation
Br[C:2]1[C:7]([N:8]([CH2:23][O:24][CH3:25])[S:9]([C:12]2[CH:17]=[CH:16][C:15]([Cl:18])=[C:14]([C:19]([F:22])([F:21])[F:20])[CH:13]=2)(=[O:11])=[O:10])=[CH:6][C:5]([Cl:26])=[CH:4][N:3]=1.C([Mg]Cl)(C)C.[C:32]([O:36][C:37]([N:39]1[C:44]2[CH:45]=[CH:46][CH:47]=[C:48]([CH:49]=[O:50])[C:43]=2[O:42][CH2:41][CH2:40]1)=[O:38])([CH3:35])([CH3:34])[CH3:33]>C1COCC1>[C:32]([O:36][C:37]([N:39]1[C:44]2[CH:45]=[CH:46][CH:47]=[C:48]([CH:49]([C:2]3[C:7]([N:8]([S:9]([C:12]4[CH:17]=[CH:16][C:15]([Cl:18])=[C:14]([C:19]([F:22])([F:21])[F:20])[CH:13]=4)(=[O:11])=[O:10])[CH2:23][O:24][CH3:25])=[CH:6][C:5]([Cl:26])=[CH:4][N:3]=3)[OH:50])[C:43]=2[O:42][CH2:41][CH2:40]1)=[O:38])([CH3:35])([CH3:33])[CH3:34]

Participants

5

Conditions

Temperature
0 °C

Procedure

To a solution of N-(2-bromo-5-chloro-pyridin-3-yl)-4-chloro-N-methoxymethyl-3-trifluoromethyl-benzenesulfonamide (2.92 g, 6.18 mmol) in THF (12 mL) under nitrogen atmosphere at −20° C. was added isopropylmagnesium chloride (2 M solution in THF, 6.5 mL, 13.0 mmol) via dropwise addition. The mixture was then stirred for 1 hour at 0° C. followed by the addition of a solution of 8-formyl-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid tert-butyl ester (273.5 mg, 1.54 mmol) in THF (2 mL) at −20° C. The mixture was stirred at room temperature overnight, quenched with saturated aqueous NH4Cl solution (5 mL), and extracted with EtOAc (2×200 mL). The combined organic extracts were washed with saturated aqueous NH4Cl solution (40 mL) and brine (40 mL), dried (Na2SO4), and concentrated under reduced pressure. The obtained residue was purified by flash column chromatography on silica gel (10% EtOAc-hexanes to 90% EtOAc-hexanes) to obtain 8-({5-chloro-3-[(4-chloro-3-trifluoromethyl-benzenesulfonyl)-methoxymethyl-amino]-pyridin-2-yl}hydroxy-methyl)-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid tert-butyl ester (590.2 mg) as yellow syrup. MS m/z: 678.0 (M+H)+.

Workup

  1. additionvia dropwise addition
  2. stirringThe mixture was stirred at room temperature overnight
  3. customquenched with saturated aqueous NH4Cl solution (5 mL)
  4. extractionextracted with EtOAc (2×200 mL)
  5. washThe combined organic extracts were washed with saturated aqueous NH4Cl solution (40 mL) and brine (40 mL)
  6. dry with materialdried (Na2SO4)
  7. concentrationconcentrated under reduced pressure
  8. customThe obtained residue was purified by flash column chromatography on silica gel (10% EtOAc-hexanes to 90% EtOAc-hexanes)

Sources & evidence

ORD record
ord-b6b728ce8be14e3395cf347b798160d8
Source dataset
uspto-grants-2013_08
Patent number
US08519135B2

Reaction notes

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