Boron tribromide → HCID 58934965, compound

HRID 855152Notes

Reaction equation

HRID 855152 reaction equation
[O:1]([C:3]1[CH:12]=[C:11]2[C:6]([CH:7]=[C:8]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH:9]([C:13]([F:16])([F:15])[F:14])[O:10]2)=[CH:5][C:4]=1[CH3:22])C.B(Br)(Br)Br>ClCCl>[OH:1][C:3]1[CH:12]=[C:11]2[C:6]([CH:7]=[C:8]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH:9]([C:13]([F:16])([F:14])[F:15])[O:10]2)=[CH:5][C:4]=1[CH3:22]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 58934521HCID 58934521, compound

Product 1

HCID 58934965HCID 58934965, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To the solution of ethyl 7-methoxyl-6-methyl-2-(trifluoromethyl)-2H-chromene-3-carboxylate (5.2 g, 16.4 mmol) in 30 mL of dry dichloromethane at −78° C. in a dry ice/acetone bath was added a solution of 1.0 M of boron tribromide (164 mL, 164 mmol) dropwise. After finishing adding, the dry ice/acetone bath was removed. The reaction was stirred at room temperature overnight. The reaction was then cooled to −78° C. in dry ice/acetone bath. 200 mL of ethanol was added dropwise. After finishing addition, the cooling bath was removed. The reaction was allowed to warm to room temperature. LC-MS indicated that the reaction was finished. The volatiles were removed on rotavapor. The residue was then purified on silica gel column with 1:9 EtOAc/hexane. The desired product was isolated as off-white solid, 3.2 g. m.p.=151.0-153.0° C. 1H NMR (CDCl3/CD3OD/300 MHZ):7.68(s, 1H), 6.97(s, 1H), 6.43(s, 1H), 5.65(q, J=7.2 Hz, 1H), 4.31(m, 2H), 2.17(s, 3H), 1.36(t, J=6.9 Hz, 3H). 19F NMR(CDCl3/CD3OD/300 MHz) −79.03(d, J=7.3 Hz). 13C(CDCl3/CD3OD/300 Mhz) 164.8, 159.4,153.3, 137.8, 131.8, 123.9(q, J=287.9 Hz), 119.4, 112.5, 111.8, 102.6, 70.9(q, J=32.9 Hz), 61.4, 15.3, 14.4. LC-MS(ES+): 303.1(M+1). MS(EI+): 302.0(M+, 80), 233(M−69, 100); High resolution MS: m/z calc. For C14H13F3O4: 302.0766(M+, theoretical), found: 302.0763.

Workup

  1. additionAfter finishing adding
  2. customthe dry ice/acetone bath was removed
  3. temperatureThe reaction was then cooled to −78° C. in dry ice/acetone bath
  4. addition200 mL of ethanol was added dropwise
  5. additionaddition
  6. customthe cooling bath was removed
  7. temperatureto warm to room temperature
  8. customThe volatiles were removed on rotavapor
  9. customThe residue was then purified on silica gel column with 1:9 EtOAc/hexane

Sources & evidence

ORD record
ord-1402f8e68ea74df9bdb4c44b4c4751ac
Source dataset
uspto-grants-2007_08
Patent number
US07259266B2

Reaction notes

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