Sulfuric Acid → HCID 86656427, compound

Temperature

50 °C

The 4-aminophenylbutyramide used in this example was obtained according to patent literature WO 02/08247 A2 or WO 03/051909 A2. Procedure was as follow: Methanol (100 ml) was charged to 4-(4-Aminophenyl)-butyric acid (from Aldrich) CAS[15118-60-2] (FW=179.22, 1 eq, 15 g, 83.7 mmol). Sulphuric acid FW=98.08 (4 eq, 334.8 mmol, 33 g) was added maintaining the temperature below 20° C. The mixture was then refluxed for one hour and concentrated by distillation at atmospheric pressure until half of methanol will be removed. The reaction mixture was then cooled to 50° C. and t-butyl-methyl ether was added maintaining the temperature above 45° C. The mixture was then gradually cooled to 0-5° C. and held at this temperature for 1 hour. The resultant crystalline product was isolated by filtration and washed by cold mixture of methanol and t-butyl-methyl ether (4:10) and cold ether and then dried under vacuum and then dried under vacuum to give methyl 4-aminophenylbutyrate hydrogensulfate as a white crystal (20.0 g, 84%).

1. customwas obtained
2. temperaturemaintaining the temperature below 20° C
3. temperatureThe mixture was then refluxed for one hour
4. concentrationconcentrated by distillation at atmospheric pressure until half of methanol
5. customwill be removed
6. additiont-butyl-methyl ether was added
7. temperaturemaintaining the temperature above 45° C
8. temperatureThe mixture was then gradually cooled to 0-5° C.
9. customThe resultant crystalline product was isolated by filtration
10. washwashed by cold mixture of methanol and t-butyl-methyl ether (4:10) and cold ether
11. customdried under vacuum
12. customdried under vacuum

ORD record

ord-87ab5f99bed74880ad8cc41afd30cf7b

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08487130B2