Acetyl chloride → 6-Isopropyl-1H-benzo[d][1,3]oxazine-2,4-dione

Participants

Reaction Steps

A mixture of 2-amino-5-isopropylbenzoic acid (30. g, 16.7 mmol) and ethyl chloroformate (1.75 mL, 18.4 mmol) in dioxane (20 mL) was heated under reflux for 2 h. After cooling, acetyl chloride (1.4 mL) was added and heating under reflux continued for another 3 h. After cooling, the mixture was evaporated and the resulting solid digested with tert-butyl methyl ether: heptane (1:1, 20 mL) by heating under reflux for 1 h. The soild was then filtered off and washed with tert-butyl methyl ether: heptane (1:1, 10 mL). Yield 3.1 g (89%). m/z 204 (M—H−).

Provenance & Evidence