Dimethylformamide → tert-Butyl 5-bromo-2-chlorobenzoate

5-bromo-2-chlorobenzoic acid (1 eq.) and anhydrous DMF (1.2 eq.) was taken up in toluene (0.9 M). To this was then added, dropwise over 5 min, oxalyl chloride (1.2 eq.) and the reaction mixture was stirred at RT for 1 h. The volatiles were then removed in vacuo and the resulting residue was taken up in toluene (0.9 M). At 0° C., potassium tert-butoxide (2.5 eq.) was added and the reaction mixture was stirred at RT for 1 h. The reaction mixture was poured into H2O and extracted with ether. The combined organic extracts were washed with brine, dried over MgSO4 and filtered. Concentration of the filtrate in vacuo afforded a pale yellow oil. Purification of the crude product thus obtained by way of flash chromatography (SiO2, Hex→85:15 (v/v) Hex:EtOAc) afforded the title compound as a light yellow oil.

1. additionTo this was then added, dropwise over 5 min
2. customThe volatiles were then removed in vacuo
3. extractionextracted with ether
4. washThe combined organic extracts were washed with brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customConcentration of the filtrate in vacuo afforded a pale yellow oil
8. customPurification of the crude product
9. customthus obtained by way of flash chromatography (SiO2, Hex→85:15 (v/v) Hex:EtOAc)

ORD-Eintrag

ord-f24f1e28b8144ab2b52b5569db03e2ef

Quelldatensatz

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08063105B2