反应详情

12.8 g of ethyl chloroformate are added while stirring to a solution of 20 g of 4-chloro-2-fluoro-5-isopropoxyaniline in 100 ml of methylene chloride at room temperature. 9.4 g of pyridine are subsequently added dropwise during 20 minutes at 20° C. while stirring and cooling. The reaction mixture is stirred for 20 minutes, washed three times with in each case 200 ml of a solution of 20 ml of 2N hydrochloric acid in 200 ml of water, dried over anhydrous sodium sulphate and evaporated to dryness under reduced pressure. There is obtained ethyl N-(4-chloro-2-fluoro-5-isopropoxyphenyl)-carbamate, m.p. 89°-91° C.

1. temperaturecooling
2. stirringThe reaction mixture is stirred for 20 minutes
3. washwashed three times with in each case 200 ml of a solution of 20 ml of 2N hydrochloric acid in 200 ml of water
4. dry with materialdried over anhydrous sodium sulphate
5. customevaporated to dryness under reduced pressure