反应 #1597023

反应方程式

oxalyl chloride

(R)-(−)-2,2-Dimethyl-5-oxo-1,3-dioxolane-4-acetic acid

5-Chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide

N,N-dimethylformamide

→

(R)-4-chloro-2-(2-chloro-4-nitrophenylcarbamoyl)phenyl 2-(2,2-dimethyl-5-oxo-1,3-dioxolan-4-yl)acetate

溶剂

chloroform

pyridine

反应条件

后处理

1. 1
   其他The progression of reaction
2. 2
   温度cooled to room temperature
3. 3
   浓缩concentrated
4. 4
   其他to remove volatiles
5. 5
   workup.ADDITIONThis residue was diluted with chloroform (10 mL)
6. 6
   workup.DISSOLUTIONhad been previously dissolved
7. 7
   其他was partitioned between 1N aqueous HCl and ethyl acetate
8. 8
   干燥The ethyl acetate solution was dried over magnesium sulfate
9. 9
   浓缩concentrated to a dark oil
10. 10
    workup.DISSOLUTIONThe residue was dissolved in chloroform
11. 11
    洗涤The product was eluted with chloroform
12. 12
    浓缩concentrated to an oil
13. 13
    其他The product was crystallized with a mixture of hexanes and ethyl acetate

实验过程

A suspension of (R)-(−)-2,2-Dimethyl-5-oxo-1,3-dioxolane-4-acetic acid (Sigma-Aldrich, St. Louis, Mo.) (2.17 g, 12.46 mmol) in chloroform (24 mL) was treated with oxalyl chloride (2.11 mL, 25 mmol) and a drop of N,N-dimethylformamide was added. The progression of reaction was monitored by the observation of gas evolution by means of a bubbler. After 2 hours at room temperature, the reaction mixture was warmed to 50° C. for 2 hours, cooled to room temperature, and concentrated to remove volatiles. This residue was diluted with chloroform (10 mL) and added to a suspension of 5-Chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide (2.04 g, 6.23 mmol) in pyridine (30 mL) in which 4-dimethylaminopyride (20 mg) had been previously dissolved. The reaction mixture was stirred at room temperature for 16 h and then was partitioned between 1N aqueous HCl and ethyl acetate. The ethyl acetate solution was dried over magnesium sulfate and concentrated to a dark oil. The residue was dissolved in chloroform and placed upon a short column of silica gel (60 mm i.d.×15 mm). The product was eluted with chloroform and concentrated to an oil. The product was crystallized with a mixture of hexanes and ethyl acetate. 1HNMR (300 MHz, DMSO-d6): δ1.456 (s, 3H), 1.495 (s, 3H), 4.939 (m, 1H), 7.352 (d, J=9 Hz, 1H, H3), 7.730 (dd, J=3.9 Hz, 1H, H4), 7.851 (d, J=3 Hz, 1H, H6), 8.110 (d, J=9 Hz, 1H, H6′), 8.255 (dd, J=3, 9 Hz, 1H, H5′), 8.411 (d, J=3 Hz, 1H, H3′), 10.481 (s, 1H, NH).

来源