Triphenylphosphine → 1-Benzyl-3-bromomethyl-4,5,6,7-tetrahydro-1H-indazole

HRID 343123Notes

Reaction equation

C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[Br:20]Br.[CH2:22]([N:29]1[C:37]2[CH2:36][CH2:35][CH2:34][CH2:33][C:32]=2[C:31]([CH2:38]O)=[N:30]1)[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1>C(Cl)(Cl)(Cl)Cl>[CH2:22]([N:29]1[C:37]2[CH2:36][CH2:35][CH2:34][CH2:33][C:32]=2[C:31]([CH2:38][Br:20])=[N:30]1)[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a stirring solution of 752 mg (2.87 mmol, 1.3 equiv) of triphenylphosphine in 10 mL of CCl4 at 0° C. is added 135 μL (2.63 mmol, 1.2 equiv) of Br2. The resulting orange-yellow suspension is stirred 10 min at 0° C., then a solution of 580 mg (2.39 mmol) of (4,5,6,7-Tetrahydro-1-benzyl-1H-indazol-3-yl) methanol in 3 mL of CCl4 is added over 2 min. The resulting solution is stirred 2.5 h at RT, and the solvent is removed in vacuo. Purification of the residue by silica gel flash column chromatography using hexane/EtOAc 5/1 as eluent afforded 76 mg of the title compound as a clear oil: 1H NMR (CDCl3, 300 MHz) δ7.32-7.24 (m, 3H), 7.10 (m, 2H), 5.17 (s, 2H), 4.49 (s, 2H), 2.48 (m, 4H), 1.74 (m, 4H); low resolution MS (FAB)m/e 305 (MH+).

Workup

stirringThe resulting solution is stirred 2.5 h at RT
customthe solvent is removed in vacuo
customPurification of the residue by silica gel flash column chromatography

Sources & evidence

ORD record: ord-2f0d7e64b0d04e4388fbc6d290523912
Source dataset: uspto-grants-1999_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05859007

Reaction notes

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