反应详情

温度

7.5 °C

10.2 g (35.9 mmol) of methyl 3-[5-(dimethylaminomethyleneamino)pyrimidin-2-yl]benzoate are suspended in 1 l of methanol. 5.3 ml (107.3 mmol) of fuming sulfuric acid are added dropwise with gentle cooling (about 5-10° C.) (note, strongly exothermic reaction). When the addition is complete, the mixture is stirred firstly at room temperature for 30 min and subsequently at an oil-bath temperature of 88°. The reaction is monitored by means of HPLC. After 20 h, the clear, dark-yellow solution is evaporated to dryness. The residue is dissolved in 600 ml of ethyl acetate and washed with 2×150 ml of 1 N NaOH and 2×1 N HCl, dried over sodium sulfate and evaporated; yield: 3 g; HPLC: Rt=2.17 min (method B); LC-MS: 300 (M+H).

1. customnote, strongly exothermic reaction)
2. additionWhen the addition
3. waitAfter 20 h
4. customthe clear, dark-yellow solution is evaporated to dryness
5. dissolutionThe residue is dissolved in 600 ml of ethyl acetate
6. washwashed with 2×150 ml of 1 N NaOH and 2×1 N HCl
7. dry with materialdried over sodium sulfate
8. customevaporated