Carbon Dioxide → 3-Iodobenzyl alcohol

Participants

Reaction Steps

Ethyl chloroformate (1.02 g, 11.1 mmol) in dry tetrahydrofuran (5 ml) was added slowly over 10 min to a stirred solution of 3-iodobenzoic acid (1.98 g, 7.98 mmol) and triethylamine (0.500 g, 11.6 mmol) in dry tetrahydrofuran at −8° (ice/salt/water bath). The yellow mixture soon became cloudy. It was shielded from light and stirred at −8° for 0.5 h, after which it was filtered to remove the triethylammonium chloride precipitate. The filtrate was added slowly to a suspension of sodium borohydride (0.795 g, 21.1 mmol) in water (30 ml) in a three necked flask, equipped with a thermometer, and connected to nitrogen, making sure that the temperature of the mixture is kept below 10° during the addition. Gas evolution (carbon dioxide) was observed. After the addition was completed, the mixture was stirred, shielded from light, at room temperature for 22 h under nitrogen. The resultant cloudy mixture was acidified with aqueous hydrochloric acid (10%) to pH˜1. The layers were separated, and the aqueous layer was extracted with ether (×3). The combined ether extract and tetrahydrofuran layer was washed with aqueous sodium hydroxide (×1, 10%) and then with water (×1). Drying with magnesium sulphate, and concentration gave 3-iodobenzyl alcohol (11) a pale yellow oil (1.02 g, 54%).

Provenance & Evidence