Methyl 2,6-Difluoro-3-nitrobenzoate → Methyl 3-amino-2,6-difluorobenzoate

10% (wt.) Pd on activated carbon (4.46 g, 4.19 mmol) was added to a 1 L flask charged with methyl 2,6-difluoro-3-nitrobenzoate (18.2 g, 83.8 mmol) under a nitrogen atmosphere. EtOH (350 mL, 0.25 M) was added, and then H2 was passed through the reaction mixture for 15 minutes. The reaction mixture was stirred under two H2 balloons overnight. The following day the reaction mixture was re-flushed with fresh H2 balloons and stirred an additional 4 hours. Upon consumption of the starting material and intermediate hydroxylamine as determined by TLC, N2 gas was flushed through the reaction mixture. The mixture was then filtered through glass microfibre filter (“GF/F”) paper twice. The volatiles were removed to afford methyl 3-amino-2,6-difluorobenzoate as an oil (15.66 g, 99%). The material was taken directly onto the next step.

1. customThe following day the reaction mixture was re-flushed with fresh H2 balloons
2. stirringstirred an additional 4 hours
3. customUpon consumption of the starting material and intermediate hydroxylamine
4. customwas flushed through the reaction mixture
5. filtrationThe mixture was then filtered through glass microfibre
6. filtrationfilter (“GF/F”) paper twice
7. customThe volatiles were removed

ORD record

ord-6c0608a119d84660a6c5c7c99536db16

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08394795B2