Benzene → HCID 54349115, compound

Participants

Reaction Steps

To a 100 mL 14/20 round bottom flask under a nitrogen atmosphere was charged 1.0 g (4.81 mmmol) of 2-bromo-4-thiazolecarboxylic acid in 10 mL of benzene, followed by the addition of 1.4 mL (19 mmol) of thionyl chloride, and a catalytic amount of dimethylformamide. The reaction was heated to reflux for 2 hours The volatiles were removed in vacuo, and this residue was then dissolved in 15 mL of methylene chloride and added dropwise to an ice-bath cooled mixture of 1.21 g (5.05 mmol) of L-glutamic acid diethyl ester, 1.41 mL (10.1 mmol) of triethylamine, and 5 mg of dimethylaminopyridine in 15 mL methylene chloride. After the addition, the ice bath was removed and the reaction was stirred at room temperature for 2 hours The reaction was diluted with methylene chloride, washed with 0.1 N hydrochloric acid, water, 5% sodium bicarbonate, water, dried over sodium sulfate, and removed in vacuo. The crude residue was purified using silica gel flash chromatography eluting with a gradient of 1:2 ethyl acetate/hexanes to 1:1 ethyl acetate/hexanes to give 0.9 g (48%) of N-[(2-bromo-5-thiazolyl)carbonyl]-L-glutamic acid diethyl ester as a yellow oil. Rf =0.30 (1:2 ethyl acetate/hexanes), 1H NMR (300 MHz, CDCl3) δ 1.24-1.34 (m, 6H), 2.15-2.32 (m, 2H), 2.47-2.55 (m, 2H), 4.12-4.30 (m, 4H), 4.64-4.71 (m, 1H), 7.97 (s, 1H).

Provenance & Evidence