Pyridine → Ethyl 3-chloro-4-methylcarbanilate

Using a method analogous to that disclosed in Example 1, Step A, of U.S. Pat. No. 4,552,585, a solution of 10.0 grams (0.071 mole) of 3-chloro-4-methylaniline in 100 mL of chloroform was stirred, and 16.7 grams (0.212 mole) of pyridine was added. Ethyl chloroformate, 9.2 grams (0.085 mole), was then added dropwise during a 20 minute period. During the addition the reaction mixture temperature was held between 25°-30° C. with external cooling. Upon completion of addition the reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was washed into a separatory funnel with 50 mL of chloroform, and the solution was washed with two 100 mL portions of water and 100 mL of aqueous 5% hydrochloric acid. The organic layer was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to a waxy solid residue. The residue was recrystallized from hexane to yield 12.2 grams of ethyl (3-chloro-4-methylphenyl)carbamate; m.p. 51°-52° C.

1. additionDuring the addition the reaction mixture temperature
2. customwas held between 25°-30° C. with external cooling
3. additionUpon completion of addition the reaction mixture
4. washThe reaction mixture was washed into a separatory funnel with 50 mL of chloroform
5. washthe solution was washed with two 100 mL portions of water and 100 mL of aqueous 5% hydrochloric acid
6. dry with materialThe organic layer was dried with magnesium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure to a waxy solid residue
9. customThe residue was recrystallized from hexane

ORD record

ord-9bf6c5b77baa4a009ac4e1a25e98fecf

Source dataset

uspto-grants-1989_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04826527