Methylparaben → (RS)-methyl 4-[2-(4,4-dimethyl-thiochroman-6-yl)-heptyloxy]-benzoate

Participants

Reaction Steps

0.25 g of (RS)-2-(4,4-dimethyl-thiochroman-6-yl)-heptanol dissolved in 15 ml THF were treated with 250 mg of triphenylphosphine, 150 mg of methyl 4-hydroxybenzoate and 0.15 ml of diethyl azodicarboxylate. The reaction mixture was heated to reflux for 6 hours. The mixture was diluted with 50 ml of ether and washed with two portions of 15 ml of water and one portion of 15 ml of sat. aq. sodium chloride solution. The organic phase was dried over MgSO4. The solvents were removed in vacuo and the resulting yellow oil was purified by flash chromatography (SiO2, 3% ethyl acetate/hexanes), giving 280 mg of (RS)-methyl 4-[2-(4,4-dimethyl-thiochroman-6-yl)-heptyloxy]-benzoate as a pale yellow oil. 1H NMR (CDCl3): 7.95 (d, J=8.9 Hz, 2H), 7.21 (d, J=1.9 Hz, 1H), 7.03 (d, J=8.1 Hz, 1H), 6.91 (dd, J=8.1, 1.9 Hz, 1H), 6.87 (d, J=8.9 Hz, 2H), 4.10-4.00 (m, 2H), 3.87 (s, 3H), 3.05-2.90 (m, 3H), 2.00-1.80 (m, 3H), 1.70-1.60 (m, 1H), 1.32 (s, 3H), 1.31 (s, 3H), 1.35-1.15 (m, 6H), 0.90-0.80 (m, 3H).

Provenance & Evidence