反应详情

To dry methanol (190 mL) is carefully added K-tert.-butylate (18.68 g, 166 mmol) followed by hydroxylamine hydrochloride (9.92 g, 143 mmol). The suspension is stirred for 30 min before 3,5-dimethyl-4-hydroxybenzonitrile (7.00 g, 147 mmol) is added. The mixture is refluxed for 32 h, then the suspension is diluted by adding 2 N aq. HCl. The solution is extracted twice with DCM (100 mL). The aq. layer is basified (pH 9) by adding solid NaHCO3 and extracted five times with DCM followed by four times with EA. The combined organic layers are dried over Na2SO4 and evaporated to dryness to give 4,N-dihydroxy-3,5-dimethyl-benzamidine (7.9 g) as a colourless solid; LC-MS: tR=0.62 min, [M+1]+=181.14.

1. additionis added
2. temperatureThe mixture is refluxed for 32 h
3. additionthe suspension is diluted
4. extractionThe solution is extracted twice with DCM (100 mL)
5. additionby adding solid NaHCO3
6. extractionextracted five times with DCM
7. dry with materialThe combined organic layers are dried over Na2SO4
8. customevaporated to dryness