Acetic Anhydride → HCID 178432095, compound

The isatoic anhydride, acetic anhydride and pyridine were combined in a round bottomed flask equipped with a thermometer, reflux condenser and protected from atmospheric moisture by a drying tube. The reaction mixture was heated to 90°-100° C for 1 hour. The reaction mixture was cooled to room temperature and the hydroxylamine-hydrochloride was added all at once. The reaction mixture was stirred at room temperature for 24 hours. Most of the pyridine was removed from the reaction product by distillation under reduced pressure. The solid residue was slurried with 150 ml of cold water. The solid was isolated and crystallized from 200 ml of methanol to give 7.4 parts (70% yield) of 4-hydroxy-2-methylquinazoline-3-oxide. It is obvious from the above that part of the reaction product may exist in the tautomeric form.

1. customequipped with a thermometer
2. temperaturereflux condenser
3. customprotected from atmospheric moisture by a drying tube
4. temperatureThe reaction mixture was heated to 90°-100° C for 1 hour
5. customMost of the pyridine was removed from the reaction product by distillation under reduced pressure
6. customThe solid was isolated
7. customcrystallized from 200 ml of methanol

ORD record

ord-2a42403fd8184eda8be36eabb4d0d5a7

Source dataset

uspto-grants-1976_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03989698