Bromide ion → HCID 10488502, compound

Participants

Reaction Steps

Magnesium turnings (2.34 g, 97.6 mmol) and THF(100 mL) are placed under N2. A small crystal of I2 and a 1 mL portion of phenethyl bromide are added, and the mixture is stirred at rt for 30 min. The reaction mixture is briefly heated with a heat gun until the iodine color is discharged. An exothermic reaction commences. Thereafter, the remaining bromide (10.5 mL, total=11.5 mL, 84.6 mmol) is added at a rate to maintain a gentle reflux (ca. 10 min). When the mixture reaches rt, the reaction apparatus is placed in an ice water bath, and tetrahydropyran-4-one (6.0 mL, 43.4 mmol) is added to the reaction mixture neat via syringe over a five minute period. The cooling bath is removed, and the reaction mixture is allowed to reach rt. The reaction mixture is worked up and purified as above with compound 17 to give the product 18. Recrystallization from hexane/CH2Cl2 gives 18 as white needles (1 crop), mp 74-75° C. (5.0 g, 37%) . 1H NMR (CDCl3) 7.40-7.10(m,5), 3.90-3.70(m,4), 2.80-2.65(m,2), 1.90-1.70(m,4), 1.55(br d,2, J=11.9), 1.46(s,1); 13C NMR (CDCl3) 142.14, 128.47, 128.28, 125.87, 68.86, 63.78, 45.13, 37.58, 28.91; MS(CI/CH4, eE=70eV) m/z 207(M+H)+,205, 190, 189 (base peak), 171, 161, 143, 119, 101, 91, 83, 71; Anal. Calcd for C13H18O2 (MW=206.3): C,75.69 H,8.80. Found: C,75.46 H,8.80.

Provenance & Evidence