反応 #164527

反応方程式

1-Amino-4,6-dimethyl-1H-pyrimidin-2-ylidene-ammonium 2,4,6-Trimethyl-benzenesulfonate

NaOH

chloroacetic acid methyl ester

→

2-Chloromethyl-5,7-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidine

収率 10.2%

溶媒

EtOH

反応条件

後処理

1. 1
   温度at reflux for 4 hours
2. 2
   濃縮After being concentrated
3. 3
   workup.ADDITIONthe residue was diluted with water (1000 mL)
4. 4
   抽出extracted with CH2Cl2 (300 mL×3)
5. 5
   洗浄The combined organic layers were washed with brine (200 mL)
6. 6
   乾燥dried over Na2SO4
7. 7
   ろ過filtered
8. 8
   濃縮concentrated under vacuum
9. 9
   その他The residue was purified by column chromatography on silica gel (petroleum ether/EtOAc=2/1)

実験手順

A mixture of 1-Amino-4,6-dimethyl-1H-pyrimidin-2-ylidene-ammonium 2,4,6-Trimethyl-benzenesulfonate (40 g, 0.1 mol) and NaOH (10 g, 0.2 mol) in 500 mL of EtOH was stirred at 50-60° C. for 1 hour. After chloroacetic acid methyl ester (16.6 g, 0.15 mol) was added, the resultant mixture was stirred at reflux for 4 hours. After being concentrated under reduce pressure, the residue was diluted with water (1000 mL) and extracted with CH2Cl2 (300 mL×3). The combined organic layers were washed with brine (200 mL), dried over Na2SO4, filtered, and concentrated under vacuum. The residue was purified by column chromatography on silica gel (petroleum ether/EtOAc=2/1) to give 2 g of 2-Chloromethyl-5,7-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidine in 9% yield. 1H NMR (300 MHz, DMSO-d6): δ8.55 (s, 1H), 6.25 (s, 2H), 4.05 (s, 3H), 3.95 (s, 3H); LC-MS (MH+): m/z=196.9, tR (min, method A)=0.52

出典