Methanesulfonic Acid → 1-Ethyl-3-[5-hydroxy-7-(2-pyridyl)-1,3-benzothiazol-2-yl]urea

HRID 1399964Notes

Reaction equation

HRID 1399964 reaction equation
C([O:8][C:9]1[CH:10]=[C:11]([C:24]2[CH:29]=[CH:28][CH:27]=[CH:26][N:25]=2)[C:12]2[S:16][C:15]([NH:17][C:18]([NH:20][CH2:21][CH3:22])=[O:19])=[N:14][C:13]=2[CH:23]=1)C1C=CC=CC=1.CS(O)(=O)=O>C(Cl)Cl>[CH2:21]([NH:20][C:18]([NH:17][C:15]1[S:16][C:12]2[C:11]([C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][N:25]=3)=[CH:10][C:9]([OH:8])=[CH:23][C:13]=2[N:14]=1)=[O:19])[CH3:22]

Participants

4

Reactant 2

HCID 6395Methanesulfonic AcidHCID 727246171-[5-Benzyloxy-7-(2-pyridyl)-1,3-benzothiazol-2-yl]-3-ethyl-urea

Product 1

HCID 727246181-Ethyl-3-[5-hydroxy-7-(2-pyridyl)-1,3-benzothiazol-2-yl]urea

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of ix (76 g, 0.187 mol) in DCM (1.7 L) was added methane sulfonic acid (270 mL, 4.17 mol) dropwise over 30 min. The mixture was stirred at RT for 3 h. The reaction was concentrated in vacuo. EtOAc (1 L) was added to the residue and this solution was poured carefully onto the crushed ice. The pH of the solution was modified to 8-9 by addition of saturated NaHCO3 solution followed by extraction with EtOAc (3×5 L). The combined organics were washed with H2O, brine, dried (Na2SO4), filtered and concentrated in vacuo. The residue was stirred in Et2O (1.0 L) for 1 h at RT and then filtered to obtain x (57.0 g, 97%). 1H-NMR (DMSO-d6, 400 MHz): δ 1.08 (t, J=7.20 Hz, 3H), 3.20 (m, 2H), 6.86 (br s, 1H), 7.0 (s, 1H), 7.46 (s, 2H), 7.96 (m, 1H), 8.10 (m, 1H), 8.76 (m, 1H), 9.59 (br s, 1H) and 10.41 (br s, 1H). MS: 315.06 [M+H]+.

Workup

  1. concentrationThe reaction was concentrated in vacuo
  2. additionEtOAc (1 L) was added to the residue
  3. additionthis solution was poured carefully onto the crushed ice
  4. additionThe pH of the solution was modified to 8-9 by addition of saturated NaHCO3 solution
  5. extractionfollowed by extraction with EtOAc (3×5 L)
  6. washThe combined organics were washed with H2O, brine
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. stirringThe residue was stirred in Et2O (1.0 L) for 1 h at RT
  11. filtrationfiltered
  12. customto obtain x (57.0 g, 97%)

Sources & evidence

ORD record
ord-95bab9b866c84b148ea871c5664add77
Source dataset
uspto-grants-2014_12
Patent number
US08906902B2

Reaction notes

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