Butanoic acid, 4-chloro-4-oxo-, methyl ester → HCID 178500572, compound

Temperature

0 °C

A 50-mL, one-neck, round bottomed flask equipped with a magnetic stirrer and a digital thermometer was charged with tert-butyl [3-(N-hydroxycarbamimidoyl)phenyl]carbamate (5.56 g, 22.1 mmol), diisopropylethylamine (4.29 g, 33.2 mmol) and THF (25 mL). The reaction mixture was then cooled to 0° C. in an ice/salt bath. 3-Carbomethoxypropionyl chloride (3.99 g, 26.6 mmol) was then added dropwise to the reaction mixture. Once the addition was complete, the cooling bath was removed and the mixture stirred at room temperature for an additional 3 h. The reaction was then concentrated under reduced pressure, the residue dissolved in ethyl acetate (60 mL), and the resulting solution washed with 2 M aqueous potassium carbonate solution (2×60 mL). Drying over sodium sulfate, filtration and concentration under reduced pressure afforded a quantitative yield of 3-tert-butyloxycarbonylamino-N-(3-carbomethoxypropionyloxy)benzamidine as a white solid that was used directly. 1H NMR (CDCl3) δ (ppm) 7.71 (s, 1H), 7.50 (m, 2H,), 7.33 (m, 2H), 6.58 (bs, 1H), 5.19 (bs, 2H), 3.71 (s, 3H), 2.83 (m, 2H), 2.75 (m, 2H), 1.52 (s, 9H).

1. customA 50-mL, one-neck, round bottomed flask equipped with a magnetic stirrer
2. additionOnce the addition
3. customthe cooling bath was removed
4. concentrationThe reaction was then concentrated under reduced pressure
5. dissolutionthe residue dissolved in ethyl acetate (60 mL)
6. washthe resulting solution washed with 2 M aqueous potassium carbonate solution (2×60 mL)
7. dry with materialDrying over sodium sulfate, filtration and concentration under reduced pressure

ORD record

ord-64b69b9b95024525817802d2b1676af5

Source dataset

uspto-grants-2005_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06924284B2