5-Chlorobenzoxazole → Benzo[D]oxazol-5-ylboronic acid

HRID 550185

반응식

HRID 550185 반응식
Cl[C:2]1[CH:3]=[CH:4][C:5]2[O:9][CH:8]=[N:7][C:6]=2[CH:10]=1.CC1(C)C(C)(C)[O:15][B:14](B2OC(C)(C)C(C)(C)O2)[O:13]1.C([O-])(=O)C.[K+].C(C1C=CC=C(C(C)C)C=1Cl=C1N=CC=N1)(C)C>C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[O:9]1[C:5]2[CH:4]=[CH:3][C:2]([B:14]([OH:15])[OH:13])=[CH:10][C:6]=2[N:7]=[CH:8]1

참가 물질

5

반응물 3

HCID 283985-ChlorobenzoxazoleHCID 517044Potassium AcetateHCID 2733548Bis(pinacolato)diborane

생성물 1

HCID 18452960Benzo[D]oxazol-5-ylboronic acid

시약·촉매·용매 1

HCID 167845palladium(II) acetate촉매

반응 조건

온도
80 °C

실험 절차

A mixture of 5-chlorobenzoxazole (0.129 g, 0.84 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane (0.4956 g, 1.95 mmol), potassium acetate (0.41 g, 4.2 mmol), 1,3-bis(2,6-diisopropylphenylimidazol-2-ylidene hydrochloride (43 mg, 0.10 mmol) and palladium acetate (11 mg, 0.05 mmol) was degassed, treated with tetrahydrofuran (10 mL) and the resulting mixture heated at 80° C. overnight. The mixture was diluted with water (100 mL), acidified to pH 6 and extracted with EtOAc (3×40 mL). The extracts were washed with water, dried and concentrated in vacuo. The residue so obtained was purified by chromatography over silica gel eluting with DCM to 10% MeCN/DCM to afford 1,3-benzoxazole-5-boronic acid, pinacol ester. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.37-1.39 (m, 12 H) 7.59 (d, J=8.34 Hz, 1 H) 7.86 (dd, J=8.08, 1.01 Hz, 1 H) 8.10 (s, 1 H) 8.26 (s, 1 H); MS (ES+): m/z 246.23 [MH+].

후처리

  1. customwas degassed
  2. additiontreated with tetrahydrofuran (10 mL)
  3. additionThe mixture was diluted with water (100 mL)
  4. extractionextracted with EtOAc (3×40 mL)
  5. washThe extracts were washed with water
  6. customdried
  7. concentrationconcentrated in vacuo
  8. customThe residue so obtained
  9. customwas purified by chromatography over silica gel eluting with DCM to 10% MeCN/DCM

출처 및 근거

ORD 기록
ord-acecb314e81b4d68972a8d03bf2958e8
출처 데이터셋
uspto-grants-2011_05
특허 번호
US07943767B2

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