反応 #87888

反応方程式

Oxalyl chloride

2,3-methylenedioxycinnamic acid

guanidine hydrochloride

dimethylformamide

→

crude product

収率 66.0%

2,3-Methylenedioxycinnamoylguanidine

収率 66.0%

溶媒

dichloromethane

chloroform

sodium hydroxide

反応条件

後処理

1. 1
   その他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
   ろ過The resulting precipitate of crude product (100 mg) was collected by filtration
5. 5
   抽出The filtrate was extracted with chloroform (3×30 mL) and ethyl acetate (20 mL)
6. 6
   洗浄The combined organic extracts were washed with 2M aqueous sodium hydroxide (20 mL), water (20 mL)
7. 7
   乾燥dried (Na2SO4)
8. 8
   濃縮concentrated under reduced pressure

実験手順

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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