Allyl bromide → HCID 68961966, compound

Temperature

0 °C

To a solution of 4-(trifluoromethyl)phenol (5.0 g, 30.86 mmol) in carbon tetrachloride (100 mL) cooled to 0° C. was added dropwise over 4 hours bromine (4.94 g, 30.86 mmol) in carbon tetrachloride (25 mL) and the reaction mixture was allowed to stir at 0° C. for 24 h. The reaction mixture was washed with 10% aqueous sodium bisulfite (100 mL) and dichloromethane (300 mL). The aqueous phase was separated and extracted with dichloromethane (2×100 mL). The combined organic extracts were washed with saturated aqueous sodium chloride (400 mL), dried (magnesium sulfate) and the solvent was removed in vacuo to give a crude oil. Purification by flash column chromatography (silica, ethyl acetate:hexanes 2:8) gave 4.69 g (63%). Treatment of 2-bromo-4-(trifluoromethyl)phenol (4.69 g, 19.5 mmol) with sodium hydride (0.86 g, 21.0 mmol 60%) and allyl bromide (2.5 g, 21.0 mmol), followed by refluxing the resultant allyl ether in mesitylene generally according to the procedure described for Intermediate 8 provided 2-allyl-6-bromo-4-(trifluoromethyl)phenol. Treatment of 2-allyl-6-bromo-4-(trifluoromethyl)phenol (3.66 g, 13.0 mmol) with 3-chloroperoxybenzoic acid (5.84 g, 26.0 mmol, 77%) followed by potassium carbonate (2.5 g, 19.5 mmol) generally according to the procedure described for Intermediate 9 afforded 3.50 g (91%) of (±)-(7-bromo-5-(trifluoromethyl)-2,3-dihydro-1-benzofuran-2-yl)methanol. Treatment of (±)-(7-bromo-5-(trifluoromethyl-2,3-dihydro-1-benzofuran-2-yl)methanol (3.5 g, 11.78 mmol) with p-toluenesulfonyl chloride (3.6 g, 17.67 mol) generally according to the procedure described for Intermediate 10 gave 5.0 g (94%) of (±)-(7-bromo-5-(trifluoromethyl)-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate as a white solid. Treatment of (±)-(7-bromo-5-(trifluoromethyl)-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate (0.30 g, 0.66 mmol) and 2-fluorophenylboronic acid (0.26 g, 2.13 mmol) generally according to the procedure described for Intermediate 35 afforded 0.11 g, (81%) of (±)-[7-(2-fluorophenyl)-5-(trifluoromethyl)-2,3-dihydro-1-benzofuran-2-yl]methyl 4-methylbenzenesulfonate. Treatment of the tosylate with sodium azide (0.21 g, 3.2 mmol) generally according to the procedure described for Intermediate 98 afforded 0.16 g (88%) of (±)-2-(azidomethyl)-5-(trifluoromethyl)-7-(2-fluorophenyl)-2,3-dihydro-1-benzofuran. Treatment of (±)-2-(azidomethyl)-5-(trifluoromethyl)-7-(2-fluorophenyl)-2,3-dihydro-1-benzofuran with polymer-supported triphenylphosphine (0.20 g, 0.76 mmol) according to the procedure described in Example 154 afforded 0.053 g (24%) of (±)-[(5-(trifluoromethyl)-7-(phenyl)-1-2,3-dihydro-1-benzofuran-2-yl)methyl]amine as a white solid, hydrochloride salt. mp >250° C.

1. washThe reaction mixture was washed with 10% aqueous sodium bisulfite (100 mL) and dichloromethane (300 mL)
2. customThe aqueous phase was separated
3. extractionextracted with dichloromethane (2×100 mL)
4. washThe combined organic extracts were washed with saturated aqueous sodium chloride (400 mL)
5. dry with materialdried (magnesium sulfate)
6. customthe solvent was removed in vacuo
7. customto give a crude oil
8. customPurification by flash column chromatography (silica, ethyl acetate:hexanes 2:8)
9. customgave 4.69 g (63%)

ORD record

ord-c20613e8cf164be6af71cfbeb70114f4

Source dataset

uspto-grants-2008_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07435837B2