反应详情

In a stream of argon gas, 2-bromotoluene (8.55 g, 0.05 mol) in dry THF (60 ml) was dropwise added to a mixture of magnesium (2.43 g, 0.1 mol) and dibromoethane (0.1 ml) in dry THF (10 ml) at 50° to 60° C. for 13 minutes. The reaction mixture was stirred at 60° to 65° C. for 1 hour, diluted with dry THF (30 ml) and cooled below 20° C. This mixture was dropwise added to oxalyl chloride (7.62 g, 0.06 mol) in dry ether (150 ml) below -50° C. over 8 minutes, followed by stirring at -75° C. for 1 hour, and filtered in a stream of argon gas at room temperature. The filtrate was concentrated under reduced pressure at room temperature. The precipitated crystals were filtered in a stream of argon gas and washed with dry ether. The filtrate and the wash liquid were combined together and the solvent was distilled off under reduced pressure to give crude 2-(2-methylphenyl)glyoxyloyl chloride (8.75 g; yield, 95.8%) as a pale brown oil.

1. temperaturecooled below 20° C
2. stirringby stirring at -75° C. for 1 hour
3. filtrationfiltered in a stream of argon gas at room temperature
4. concentrationThe filtrate was concentrated under reduced pressure at room temperature
5. filtrationThe precipitated crystals were filtered in a stream of argon gas
6. washwashed with dry ether
7. distillationthe solvent was distilled off under reduced pressure