Methanesulfonic Acid → Methanesulfonic Acid

HRID 2294628Notes

Reaction equation

HRID 2294628 reaction equation
[B:1]([F:4])([F:3])[F:2].[CH3:5][CH2:6][O:7][CH2:8][CH3:9].[Cl-].[Al+3].[Cl-].[Cl-].[CH3:14][S:15]([OH:18])(=[O:17])=[O:16].FC(F)(F)C(O)=O.[BH4-:26].[Na+]>C1COCC1>[B:1]([F:4])([F:3])[F:2].[CH3:5][CH2:6][O:7][CH2:8][CH3:9].[CH3:14][S:15]([OH:18])(=[O:17])=[O:16].[BH3:26].[O:7]1[CH2:8][CH2:9][CH2:5][CH2:6]1

Participants

9

Reactant 5

HCID 6395Methanesulfonic AcidHCID 6422Trifluoroacetic acidHCID 8000Boron trifluoride etherateHCID 4311764Sodium borohydride2×HCID 6451240Aluminum(III) Chloride

Product 3

HCID 6395Methanesulfonic AcidHCID 8000Boron trifluoride etherateHCID 2723981Borane;tetrahydrofuran

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Step E comprises reduction of the amide carbonyl of compound VI by slowly adding a Lewis acid such as boron trifluoride etherate or aluminum chloride or an anhydrous strong acid such as methanesulfonic acid or trifluoroacetic acid to a stirred slurry of VI and sodium borohydride in dry THF at about -5° C. to about +5° C. followed by stirring about 4 to 6 hours at about -5° to +5° C. followed by 12 to 18 hours at about 25°-40° C. On completion, the reaction mixture is slowly added to cooled dilute acid followed by isolation by standard procedures if desired. As one skilled in the art would appreciate, the above reaction with sodium borohydride in dry THF and an acid such as boron trifluoride etherate or methanesulfonic acid produces borane-tetrahydrofuran in the process of forming compound VII. Alternatively, compound VII can be formed by reducing compound VI with borane-tetrahydrofuran or borane-dimethyl sulfide, without use of the acid.

Workup

  1. customat about -5° C. to about +5° C.
  2. waitfollowed by 12 to 18 hours at about 25°-40° C
  3. additionOn completion, the reaction mixture is slowly added
  4. temperatureto cooled
  5. additiondilute acid

Sources & evidence

ORD record
ord-f940675f1c7e40698d403170fc26f08c
Source dataset
uspto-grants-1997_11
Patent number
US05688968

Reaction notes

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