Potassium Hydroxide → HCID 58418749, compound

Participants

Reaction Steps

To a mixture of sodium ethoxide obtained from 13.7 g (0.60 mol) of sodium metal and 375 ml of dry ethanol and 193 g (0.50 mol) of diethyl (2-bromo-4-tert-butylbenzyl)malonate 65.5 g (0.60 mol) of ethyl bromide was added dropwise by vigorous stirring. This mixture was refluxed for 4 hours, then cooled, and a solution of 100 g of KOH in 270 ml of water was added. The obtained mixture was refluxed for 5 hours, then ethanol was distilled off. A mixture of the obtained solution and 1.5 liters of cold water was acidified by 1 M HCl to pH 1. The precipitate was decanted and then dissolved in 500 ml of ether. This solution was evaporated to dryness, and the residue was decarboxilated for ca. 2 hours at 180° C. To the obtained 2-(2-bromo-4-tert-butylbenzyl)butanoic acid 128 ml (209 g, 1.76 mol) of thionyl chloride was added. The resulting mixture was stirred for 12 hours at room temperature. An excess of thionyl chloride was distilled off. Fractional rectification of the residue gave 116 g (70%) of yellowish liquid, b.p. 137° C.-142° C./1 mm Hg. Anal. calc. for C15H20BrClO: C, 54.32; H, 6.08. Found: C, 54.43; H, 6.20. 1H NMR (CDCl3): δ 7.54 (d, J=1.9 Hz, 1H, 3-H in C6H3), 7.25 (dd, J=8.0 Hz, J=1.9 Hz, 1H, 5-H in C6H3), 7.16 (d, J=8.0 Hz, 1H, 6-H in C6H3), 3.24-3.06 (m, 2H, CH2CHCH2Me), 2.93 (dd, J=13.6 Hz, J=6.1 Hz, 1H, CHCH2Me), 1.89-1.69 (m, 2H, CH2Me), 1.28 (s, 9H, tBu), 1.02 (t, J=7.5 Hz, CH2Me). 13C{1H} NMR (CDCl3): δ 176.4, 152.1, 133.9, 130.9, 130.1, 124.7, 124.4, 58.3, 37.1, 34.5, 31.1, 24.9, 11.0.

Provenance & Evidence