Chloroform → HCID 53934247, compound

HRID 52264Notes

Reaction equation

HRID 52264 reaction equation
Cl.[F:2][C:3]1[C:12]2[O:11][CH2:10][C@H:9]([N:13]([CH:17]([CH3:19])[CH3:18])[CH2:14][CH2:15][CH3:16])[CH2:8][C:7]=2[C:6]([O:20]C)=[CH:5][CH:4]=1.B(Br)(Br)Br.C(Cl)(Cl)Cl>C(Cl)Cl>[F:2][C:3]1[C:12]2[O:11][CH2:10][C@H:9]([N:13]([CH:17]([CH3:19])[CH3:18])[CH2:14][CH2:15][CH3:16])[CH2:8][C:7]=2[C:6]([OH:20])=[CH:5][CH:4]=1

Participants

5

Reactant 3

HCID 6212ChloroformHCID 25134Boron tribromideHCID 70145878HCID 70145878, compound

Product 1

HCID 53934247HCID 53934247, compoundYield 97%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-40 °C

Procedure

(R)-8-Fluoro-3-(N-isopropyl-N-propylamino)-5-methoxy-3,4-dihydro-2H-1-benzopyran hydrochloride (1.03 g, 3.24 mmol) was dissolved in anhydrous CH2Cl2 (30 mL) and cooled to -40° C. To the solution was BBr3 (0.77 mL, 8.1 mmol), dissolved in anhydrous CH2Cl2 (5 mL), added dropwise. The cooling-bath was removed and after 3 h at room temperature the reaction was complete. The reaction was poured out onto an ice/2M NH3 solution and the mixture was extracted, twice, with diethyl ether. The combined ether portions were treated with brine, dried (Na2SO4), filtered, and the solvent removed in vacuo to give the crude residue. Chromatography on silica (eluent: 20% ethyl acetate/hexane) gave 0.84 g (97% yield) of the title compound as a clear oil [α]21D =-94.2° (C=0.1 CHCl3) GC-MS (70 eV) M=267 (26%). The hydrochloride salt was made by dissolving the pure base in diethyl ether and dropping an excess of an ethereal HCl solution. The salt was recrystallized from CHCl3 /diethyl ether/ethyl acetate to give a white solid. Mp: 220°-2° C.

Workup

  1. additionadded dropwise
  2. customThe cooling-bath was removed and after 3 h at room temperature the reaction
  3. additionThe reaction was poured out onto an ice/2M NH3 solution
  4. extractionthe mixture was extracted
  5. additionThe combined ether portions were treated with brine
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. customthe solvent removed in vacuo
  9. customto give the crude residue

Sources & evidence

ORD record
ord-4c754d08108a4c85ab10a370bb40a840
Source dataset
uspto-grants-1997_04
Patent number
US05616610

Reaction notes

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