N-(6-Maleimidocaproyloxy)succinimide

6-Maleimidohexanoic acid N-hydroxysuccinimide ester(ECMS) is a useful protective group in antibody drug conjugates.

Under nitrogen protection, 4.7 g (22 mmol) of MC and 25 g (22 mmol) of HOSu were added to 50 ml of acetonitrile.Another 4.5 g (22 mmol) of DCC was dissolved in 25 ml of acetonitrile, Keeping the internal temperature around 0°C, It was slowly dropped into the reaction solution.The reaction solution was reacted at 0°C for 2 hours and then reacted overnight at room temperature.filter, The filter cake was washed with acetonitrile 10ml×3.The filtrate was concentrated to dryness under reduced pressure.The resulting oil was dried under reduced pressure at room temperature for 6 h to give 6.4 g of light brown solid.Yield 95percent.Dicyclohexyl-carbodiimide (2.68 g, 13.02 mmol) and N-hydroxysuccinimide (1 .36 g, 1 1 .84 mmol) are added at room temperature to a stirrer solution of compound [4] (2.5 g, 1 1 .84 mmol) in anhydrous dichloromethane (15 mL) and the mixture stirred at room temperature for 3 hours. The white solid is filtered with dichloromethane to remove the dicyclohexylurea, the organic phase is washed with HCI 0.1 N and water, then dried over anhydrous sodium sulfate and the solvent removed by rotatory evaporation. The resulting residue is subjected to flash column chromatography with a medium pressure system Sepacore® Buchi (silica gel; gradient A: petroleum ether/B: ethyl acetate; Bpercent 0-80 in 15 minutes) to give the activated acid [5] as a white solid, 2.4 g (70percent). MS: m/z 309 [M+H]To a stirred solution of 6-(2, 5-dioxo-2, 5-dihydro-lH-pyrrol-l-yl)hexanoate (3.08 g, 14.6 mmol, 1.0 eq) and N-hydroxysuccinimide (1.76 g, 15.3 mmol, 1.05 eq) in EtOAc (30 mL) at 0 °C, was added dicyclohexylcarbodiimide (3.16 g, 15.3 mmol, 1.05 eq). The reaction was then allowed to warm to rt. After 20 h, the reaction was filtered and washed with EtOAc and the filtrate concentrated. The residue was purified by flash chromatography to yield the title compound (2.16 g, 48percent) as a clear oil that solidified slowly to a waxy white solid. NMR (400 MHz, Chloroform-i/) δ 6.71 (s, 2H), 3.56 (t, J = 7.2 Hz, 2H), 2.86 (s, 4H), 2.63 (t, J = 7.4 Hz, 2H), 1.80 (p, J= 7.4 Hz, 2H), 1.73 - 1.57 (m, 2H), 1.50 - 1.35 (m, 2H). m/z calcd. for CTo a stirred solution of 6-(2, 5-dioxo-2, 5-dihydro-1H-pyrrol-l-yl)hexanoate (3.08 g, 14.6 mmol, 1.0 eq) and N-hydroxysuccinimide (1.76 g, 15.3 mmol, 1.05 eq) in EtOAc (30 mL) at 0 °C, was added dicyclohexylcarbodiimide (3.16 g, 15.3 mmol, 1.05 eq). The reaction was then allowed towarm to rt. After 20 h, the reaction was filtered and washed with EtOAc and the filtrate concentrated. The residue was purified by flash chromatography to yield the title compound (2.16 g, 48percent) as a clear oil that solidified slowly to a waxy white solid. ‘H NMR (400 MHz, Chloroform-d) ö 6.71 (s, 2H), 3.56 (t, J = 7.2 Hz, 2H), 2.86 (s, 4H), 2.63 (t, J = 7.4 Hz, 2H), 1.80 (p, J = 7.4 Hz, 2H), 1.73 — 1.57 (m, 2H), 1.50 1.35 (m, 2H). m/z calcd. for C, 4H, 6N206 = 308.10. Found [M+H] = 309.13. Rf= 0.28 (50percent EtOAc/Hex)6-Maleimidohexanoic acid N-hydroxysuccinimide ester 4. Sodium bicarbonate (0.0512 g, 0.483 mmol ) was added to a solution of 6-maleimidocaproic acid (0.211 g, 1.000 mmol) in DI water (10 mL). After the reagents were dissolved in DI water, the DI water was evaporated by blowing with air. The resulting solid was dissolved in anhydrous DMF (3 mL) and the solution was cooled to 0 °C. Disuccinimide carbonate (0.282 g, 1.10 mmol) was added into the solution and the reaction was stirred at 0 °C for 1 h. CH

Molecular Weight:308.29
XLogP3:-0.5
Hydrogen Bond Acceptor Count:6
Rotatable Bond Count:8
Exact Mass:308.10083623
Monoisotopic Mass:308.10083623
Topological Polar Surface Area:101
Heavy Atom Count:22
Complexity:520
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes