Triethylamine → 1-(1,3-Dioxaindan-4-yl)ethan-1-one

Participants

Reaction Steps

To a solution of 1-benzo[1,3]dioxol-4-ylethanol (11 g, 66.3 mmol) in 100 mL of THF was added 17.26 g of manganese dioxide (MnO2) in one portion and reaction was monitored by TLC. After several hours, TLC showed some product but significant alcohol left. More manganese dioxide was added and the solution stirred. TLC then showed mostly product but a significant amount of alcohol. The reaction mixture was then filtered through a bed of diatomaceous earth and the filtrate was concentrated in vacuo to give an oil that mostly crystallized on standing. To 9.24 mL of a solution of oxalyl chloride in 120 mL of dichloromethane at −60° C. was added a solution of 15 mL of DMSO in 20 mL of dichloromethane. After 10 minutes, a solution of above alcohol/ketone mixture (53 mmol) in 20 mL of dichloromethane was added, followed 15 minutes later by 44.3 mL of triethylamine. The reaction was allowed to slowly warm to room temperature overnight. The reaction mixture was then poured onto ice and the organic layer was washed with five 100 mL portions of water, then brine, and then dried over magnesium sulfate. The organics were concentrated in vacuo to leave tan solids and the solids were triturated with hexanes, collected by filtration, and dried to give 9.33 g (85.8% yield) of 1-benzo[1,3]dioxol-4-ylethanone.

Provenance & Evidence