反应 #87888

反应方程式

Oxalyl chloride

2,3-methylenedioxycinnamic acid

guanidine hydrochloride

dimethylformamide

→

crude product

收率 66.0%

2,3-Methylenedioxycinnamoylguanidine

收率 66.0%

溶剂

dichloromethane

chloroform

sodium hydroxide

反应条件

后处理

1. 1
   其他the resulting solution was evaporated to dryness under reduced pressure
2. 2
   workup.DISSOLUTIONThe residue was dissolved in dry tetrahydrofuran (5 mL)
3. 3
   workup.STIRRINGThe reaction was stirred at room temperature for 1 hour
4. 4
   过滤The resulting precipitate of crude product (100 mg) was collected by filtration
5. 5
   萃取The filtrate was extracted with chloroform (3×30 mL) and ethyl acetate (20 mL)
6. 6
   洗涤The combined organic extracts were washed with 2M aqueous sodium hydroxide (20 mL), water (20 mL)
7. 7
   干燥dried (Na2SO4)
8. 8
   浓缩concentrated under reduced pressure

实验过程

Oxalyl chloride (0.68 mL, 7.8 mmol) was added to a suspension of 2,3-methylenedioxycinnamic acid (500 mg, 2.6 mmol) in dichloromethane (5 mL) containing a drop of dimethylformamide. The mixture was stirred for 2.5 hours and the resulting solution was evaporated to dryness under reduced pressure. The residue was dissolved in dry tetrahydrofuran (5 mL) and added to a solution of guanidine hydrochloride (1.24 g, 13 mmol) in 2M aqueous sodium hydroxide (8 mL). The reaction was stirred at room temperature for 1 hour and chloroform was then added. The resulting precipitate of crude product (100 mg) was collected by filtration. The filtrate was extracted with chloroform (3×30 mL) and ethyl acetate (20 mL). The combined organic extracts were washed with 2M aqueous sodium hydroxide (20 mL), water (20 mL), dried (Na2SO4) and concentrated under reduced pressure to give a further quantity of crude product (400 mg). The two crops of crude product were combined, suspended in chloroform (10 mL) and stirred vigorously for 20 minutes. The resulting 2,3-methylenedioxycinnamoylguanidine (420 mg) was collected by filtration and dried under vacuum.

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