[7-(5,6-Dihydro-[1,4]dioxin-2-yl)-4-methoxy-benzothiazol-2-yl]-carbamic acid ethyl ester → (+)-(7-[1,4]Dioxan-2-yl-4-methoxy-benzothiazol-2-yl)-carbamic acid ethyl ester

Participants

Reaction Steps

To a stirred solution of 12.0 g (35.7 mmol) [7-(5,6-dihydro-[1,4]dioxin-2-yl)-4-methoxy-benzothiazol-2-yl]-carbamic acid ethyl ester in 600 ml dioxane and 12 ml acetic acid was added 12 g of 10% palladium on charcoal and the mixture was then stirred for 48 h at room temperature under a 10 bar atmosphere of hydrogen. The mixture was then filtered, washing with dioxane, and the filtrate concentrated in vacuo. Flash chromatography (1/1 acetone/dichloromethane) followed by trituration in ether and hexane afforded 7.50 g (62%) (±)-(7-[1,4]dioxan-2-yl-4-methoxy-benzothiazol-2-yl)-carbamic acid ethyl ester as a white solid. ES-MS m/e (%): 339 (M+H+, 100).

Provenance & Evidence