Triethylamine → 2-Chloro-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoic acid methyl ester

Temperature

10 °C

Crude 2-chloro-4-[[(2,5-dioxo-1-pyrrolidinyl)oxy]carbonyl]benzoic acid methyl ester (Example 73; ˜35 g, 0.1 mol) was charged to a 1 L round bottom flask equipped with a magnetic stirrer, ice cooling bath and a argon inlet tube, using dimethylformamide (350 mL) to complete the transfer. The mixture was cooled to about 10° C., then with stirring in an argon atmosphere, 3-hydroxybenzylamine hydrochloride salt (Example 69; 18.35 g, 0.115 mol) and triethylamine (35 mL, 0.25 mol) were added in rapid succession. A precipitate began to form immediately. After the reaction was stirred at ambient temperature overnight, the volatiles were removed under reduced pressure (<0.5 mm). The oily residue was taken up in ethyl acetate (600 mL) and washed in turn with 0.5N hydrochloric acid (400 mL), brine (300 mL), saturated sodium bicarbonate solution (2×300 mL) and brine (300 mL). Each aqueous layer was back-extracted in turn with ethyl acetate (2×300 mL), then the combined organic extracts were dried (MgSO4) and evaporated to give crude 2-chloro-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoic acid methyl ester (˜32 g) as an off-white solid.

1. customequipped with a magnetic stirrer, ice cooling bath and a argon inlet tube
2. additionwere added in rapid succession
3. customto form immediately
4. customthe volatiles were removed under reduced pressure (<0.5 mm)
5. washwashed in turn with 0.5N hydrochloric acid (400 mL), brine (300 mL), saturated sodium bicarbonate solution (2×300 mL) and brine (300 mL)
6. extractionEach aqueous layer was back-extracted in turn with ethyl acetate (2×300 mL)
7. dry with materialthe combined organic extracts were dried (MgSO4)
8. customevaporated

ORD record

ord-a2bba1f72218430bbaee1cb917944f2c

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06515124B2