Reaction #2460303

Reaction equation

1,3-dicyclohexyl-carbodiimide

thioxanthen-9-one-2-carboxylic acid

2-hydroxyethylmethacrylate

4-dimethylamino-pyridine p-toluenesulfonic acid salt

→

pale yellow solid

Yield 17.0%

(2-methacryloxyethyl)thioxanthen-9-one-2-carboxylate

Yield 17.0%

Solvents

dichloromethane

Conditions

Workup

1. 1
   Temperaturethe reaction mixture was warmed to ambient and
2. 2
   FiltrationThe precipitated urea by product was filtered
3. 3
   Washthe filtrate was washed successively with 10% aqueous HCl, 10% aqueous NaHCO3, water, and brine
4. 4
   Concentrationconcentrated
5. 5
   OtherThe product was purified by column chromatography

Procedure

A mixture of thioxanthen-9-one-2-carboxylic acid (3.8 g, 19.8 mmol), 2-hydroxyethylmethacrylate (7.7 g, 59.3mmol), 4-dimethylamino-pyridine p-toluenesulfonic acid salt (2.3 g, 7.9mmol), and anhydrous dichloromethane (31 mL) is cooled to 0° C. under nitrogen and treated with 1,3-dicyclohexyl-carbodiimide (2.1 g, 10.1 mmol). After 15 min, the reaction mixture was warmed to ambient and stirred for 12 h. The precipitated urea by product was filtered, and the filtrate was washed successively with 10% aqueous HCl, 10% aqueous NaHCO3, water, and brine. The solution was dried (Na2SO4)and concentrated to deposit yellow oil. The product was purified by column chromatography to provide 500 mg of a pale yellow solid (17% of theory). 1H (CDCl3): δ 1.99 (s, 3H), 4.60 (dd, 4H), 5.60 (s, 1H), 6.20 (s, 1H), 7.60 (m, 4H), 8.20 (d, 1H), 8.70 (d, 1H), 9.30 (s, 1H).

Source