Trifluoroacetic acid → HCID 57748288, compound

Participants

Reaction Steps

A mixture of methyl 5-amino-4-iodo-2-(trifluoromethyl)benzoate (desired) and methyl 3-amino-4-iodo-2-(trifluoromethyl)benzoate as obtained in step 4 (392 mg, 1.14 mmol) was dissolved in 1,2-dichloroethane (12 mL) and was treated with trifluoroacetic acid (0.5 mL, 6.73 mmol), 3-pentanone (0.36 mL, 3.40 mmol) and sodium triacetoxyborohydride (724 mg, 3.42 mmol) at 45° C. for 0.5 h. GCMS indicated complete conversion of desired isomer to required product. After a further 0.5 h at 45° C., the reaction mixture was cooled to ambient temperature and was quenched with 1N sodium hydroxide (5 mL) and saturated sodium bicarbonate and was partitioned with dichloromethane. The aqueous portion was extracted with dichloromethane. The combined organic portion was washed with brine, dried over magnesium sulfate, then filtered and concentrated to afford a yellow oil which was purified by column chromatography (silica gel, 10-40% dichloromethane in hexanes) to afford pure methyl 4-iodo-5-(pentan-3-ylamino)-2-(trifluoromethyl)benzoate (330 mg, 0.795 mmol, 70% yield) as a pale yellow oil. 1H NMR (400 MHz, CDCl3): δ 7.95 (s, 1H), 6.79 (s, 1H), 4.44 (d, 1H), 3.92 (s, 3H), 3.44-3.34 (m, 1H), 1.73-1.48 (m, 4H), 0.95 (t, 6H); GCMS for C14H17F31NO2: 415 (M+).

Provenance & Evidence