Furosemide → (rac)-(R*,S*)-2-((2-(3,5-difluorophenyl)-2-hydroxy-1-methylethyl)amino)-(R)-2-methylethyl 5-(aminosulfonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoate

HRID 2357727Notes

Reaction equation

HRID 2357727 reaction equation
[OH:1][CH2:2][C@H:3]([NH:5][C@@H:6]([CH3:17])[C@@H:7]([C:9]1[CH:14]=[C:13]([F:15])[CH:12]=[C:11]([F:16])[CH:10]=1)[OH:8])[CH3:4].[CH:18]1[CH:19]=[C:20]([CH2:23][NH:24][C:25]2[C:30]([C:31](O)=[O:32])=[CH:29][C:28]([S:34]([NH2:37])(=[O:36])=[O:35])=[C:27]([Cl:38])[CH:26]=2)[O:21][CH:22]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>O.C1C=CC=CC=1.C1(C)C=CC=CC=1>[NH2:37][S:34]([C:28]1[C:27]([Cl:38])=[CH:26][C:25]([NH:24][CH2:23][C:20]2[O:21][CH:22]=[CH:18][CH:19]=2)=[C:30]([CH:29]=1)[C:31]([O:1][CH2:2][C@H:3]([NH:5][C@H:6]([CH3:17])[C@H:7]([C:9]1[CH:10]=[C:11]([F:16])[CH:12]=[C:13]([F:15])[CH:14]=1)[OH:8])[CH3:4])=[O:32])(=[O:35])=[O:36]

Participants

7

Reactant 3

HCID 3440Furosemide2×HCID 6101p-Toluenesulfonic acidHCID 68457326(rac)-(R*,S*)-2-((2-hydroxy-(R)-1-methylethyl)amino)-1-(3,5-difluorophenyl)propanol

Product 1

HCID 131728258(rac)-(R*,S*)-2-((2-(3,5-difluorophenyl)-2-hydroxy-1-methylethyl)amino)-(R)-2-methylethyl 5-(aminosulfonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoate

Reagents, catalysts & solvents 3

HCID 241BenzeneSolvent3×HCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

The free base of (rac)-(R*,S*)-2-((2-hydroxy-(R)-1-methylethyl)amino)-1-(3,5-difluorophenyl)propanol (21) (0.023 mole) and benzene (30 mL) (or toluene) is added to a round-bottomed flask. Furosemide (5-(aminosulfonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoic acid (10), (Aldrich) (0.025 mole), benzene (30 mL), and p-toluenesulfonic acid (0.026 mole) catalyst is added to the flask. A Dean-Stark trap is filled with benzene, and the contents of the flask is refluxed with stirring for several hours or until no additional water is collected in the trap. The reaction is cooled, extracted with sodium bicarbonate solution, washed with water, and then with a saturated sodium chloride solution. The organic layer is dried over sodium sulfate, filtered and concentrated in vacuo to give crude product, which may be purified by column chromatography on silica gel with hexanes/ethyl acetate as eluent. The fractions that contain pure product may be combined and spin evaporated in vacuo to give a solid that may be recrystallized to give (rac)-(R*,S*)-2-((2-(3,5-difluorophenyl)-2-hydroxy-1-methylethyl)amino)-(R)-2-methylethyl 5-(aminosulfonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoate (210). [See eg., Sandier et al., Organic Functional Group Preparations, p. 249 (1968)]

Workup

  1. temperaturethe contents of the flask is refluxed
  2. customis collected in the trap
  3. temperatureThe reaction is cooled
  4. extractionextracted with sodium bicarbonate solution
  5. washwashed with water
  6. dry with materialThe organic layer is dried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customto give crude product, which
  10. custommay be purified by column chromatography on silica gel with hexanes/ethyl acetate as eluent
  11. customspin evaporated in vacuo
  12. customto give a solid
  13. customthat may be recrystallized

Sources & evidence

ORD record
ord-fdd6e9b5e1014390969b02c2afbb7b03
Source dataset
uspto-grants-2010_07
Patent number
US07763612B2

Reaction notes

Loading…