3,4-dihydro-2H-pyran → 2-(4-Bromobutoxy)tetrahydro-2H-pyran

3,4-Dihydro-2H-pyran (8.0 g, 95.36 mmol) was added to a 0° C. solution of 4-bromobutan-1-ol (12.0 g, 79.47 mmol) in dichloromethane (150 mL) followed by p-toulenesulphonic acid (20 mg). After 1 h, the reaction was carefully quenched with sat. aq. NaHCO3 solution (5 mL), washed with water (100 mL), brine (70 mL), and concentrated in vacuo. The residue was purified by SiO2 column chromatography using 2% EtOAc/hexanes as eluent to give 2-(4-bromobutoxy)tetrahydro-2H-pyran (16.57 g, 88%) as colorless oil. TLC: 10% EtOAc/hexanes, Rf≈0.50; 1H NMR (CDCl3, 300 MHz) δ 4.58 (t, J=2.5 Hz, 1H), 3.90-3.72 (m, 2H), 3.38-3.50 (m, 4H), 1.92-2.04 (m, 2H), 1.65-1.80 (m, 4H), 1.60-1.50 (m, 4H). Lit. ref: G. L. Kad; I. Kaur; M. Bhandari; J. Singh; J. Kaur Organic Process Research & Development 2003: 7, 339.

1. customthe reaction was carefully quenched with sat. aq. NaHCO3 solution (5 mL)
2. washwashed with water (100 mL), brine (70 mL)
3. concentrationconcentrated in vacuo
4. customThe residue was purified by SiO2 column chromatography

ORD record

ord-f2c29ea9edc7419f9e17d5e0121330ac

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09272991B2