反应详情

6.0 g of N-diaminomethylene-2-methyl-4-ethynyl-5-methylsulfonylbenzamide, m.p. 223°-226° [obtainable by reaction of methyl 2-methyl-4-bromo-5-methylsulfonyl-benzoate with Li acetylide to give methyl 2-methyl-4-ethynyl-5-methylsulfonyl-benzoate and subsequent reaction with guanidine] are dissolved in 300 ml of DMF and hydrogenated in the presence of 450 mg of Pd-CaCO3 (Lindlar catalyst) for 15 minutes in a stream of hydrogen (p=1 bar). Customary working up gives N-diaminomethylene-2-methyl-4-ethenyl-5-methylsulfonyl-benzamide).