Carbon tetrabromide → t-butyl (1R)-2-bromo-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamate

HRID 1874624Notes

Reaction equation

HRID 1874624 reaction equation
O[CH2:2][C@H:3]([NH:17][C:18](=[O:24])[O:19][C:20]([CH3:23])([CH3:22])[CH3:21])[C:4]1[CH:9]=[CH:8][C:7]([O:10][CH2:11][CH:12]([CH3:16])[CH2:13][CH2:14][CH3:15])=[CH:6][CH:5]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(Br)(Br)(Br)[Br:45]>O1CCCC1>[Br:45][CH2:2][C@H:3]([NH:17][C:18](=[O:24])[O:19][C:20]([CH3:23])([CH3:22])[CH3:21])[C:4]1[CH:9]=[CH:8][C:7]([O:10][CH2:11][CH:12]([CH3:16])[CH2:13][CH2:14][CH3:15])=[CH:6][CH:5]=1

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 67433195t-butyl (1R)-2-hydroxy-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamate

Product 1

HCID 86658396t-butyl (1R)-2-bromo-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamateYield 100%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of t-butyl (1R)-2-hydroxy-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamate (15 g, 44.5 mmol), prepared according to the procedure described in example 1, in anhydrous tetrahydrofuran (200 mL) was added triphenylphosphine (17.49 g, 66.7 mmol) and carbon tetrabromide (22.11 g, 66.7 mmol). The reaction mixture was stirred at room temperature for 2 h. The mixture was filtered through a pad of diatomaceous earth (Celite®) and the filtrate was concentrated to afford yellow residue which was purified by column chromatography on silica gel (20→30% ethyl acetate in hexanes) to afford t-butyl (1R)-2-bromo-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamate (17.8 g, 100% yield) as a colorless solid: 1H NMR (400 MHz, CDCl3) δ 7.18 (d, J=8.8 Hz, 2H), 6.86 (d, J=8.6 Hz, 2H), 5.05 (br. s., 1H), 4.91 (br. s., 1H), 3.78 (dd, J=8.8, 5.8 Hz, 1H), 3.68 (dd, J=9.1, 6.8 Hz, 1H), 3.65 (d, J=5.0 Hz, 1H), 1.86-1.97 (m, 1H), 1.60 (d, J=7.3 Hz, 1H), 1.42 (s, 9H), 1.14-1.51 (m, 4H), 0.99 (d, J=6.5 Hz, 3H), 0.90 (t, J=7.3 Hz, 3H); LRMS (ESI) m/e 400.2 [(M+H)+, calcd for C19H31NO3Br 400.1].

Workup

  1. filtrationThe mixture was filtered through a pad of diatomaceous earth (Celite®)
  2. concentrationthe filtrate was concentrated
  3. customto afford yellow residue which
  4. customwas purified by column chromatography on silica gel (20→30% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-1da0129d7e714e038833bb70344968c4
Source dataset
uspto-grants-2012_11
Patent number
US08304577B2

Reaction notes

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