p-Toluenesulfonic acid → 4-methoxy-3-[(N-chloro-benzimidoyl)-amino]-benzoic acid methyl ester

Temperature

180 °C

Anhydrous p-toluene sulfonic acid (41.99 g, 220.8 mmol) was melted at 120° C. and 3-amino-4-methoxy benzoic acid methyl ester (20 g, 110.38 mmol) obtained in step 1 and benzonitrile (22.77 g, 220.8 mmol) were added thereto and stirred at 180° C. for 5 hours. The resulting solution was cooled to room temperature and the reaction was stopped by adding NaHCO3 thereto. The resulting mixture was extracted with ethyl acetate, the extract was dried over MgSO4 and concentrated under a reduced pressure. The concentrate was dissolved in 50% methanol and 5% NaOCl (56 Ml, 37.65 mmol) was added dropwise thereto. After 5 min, the resulting mixture was extracted with ethyl acetate, the extract was dried over MgSO4 and concentrated under a reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent—MeOH/CDCl3=5:95, Merck, Silicagel 60) to obtain the title compound (31 g, 25.10 mmol) in a yield of 88%;

1. additionwere added
2. temperatureThe resulting solution was cooled to room temperature
3. extractionThe resulting mixture was extracted with ethyl acetate
4. dry with materialthe extract was dried over MgSO4
5. concentrationconcentrated under a reduced pressure
6. dissolutionThe concentrate was dissolved in 50% methanol
7. waitAfter 5 min
8. extractionthe resulting mixture was extracted with ethyl acetate
9. dry with materialthe extract was dried over MgSO4
10. concentrationconcentrated under a reduced pressure
11. customThe resulting residue was purified by silica gel column chromatography (eluent—MeOH/CDCl3=5:95, Merck, Silicagel 60)

ORD record

ord-355faa56b66949f6b215a49bf9a90720

Source dataset

uspto-grants-2007_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07179832B2