反应详情

The above nitro compound (8.4 g, 0.04 mol) is dissolved in 150 ml of methanol and hydrogenated (initial hydrogen pressure=51 psi) in the presence of 0.5 g of Raney nickel until the theoretical uptake of hydrogen is observed. The catalyst is removed by filtering; the filtrate is evaporated in vacuo to give 7.4 g (0.04 mol) of a purple oil (characterized by its IR-spectrum) of 2-(4-amino-1,3-dimethyl-5-pyrazolyl)imidazoline. This amine (7.4 g, 0.04 mol) is stirred under reflux 1.5 hr in a mixture of 20 ml absolute ethanol, 50 ml of triethylorthoformate and 1 ml of methanesulfonic acid. The mixture is evaporated in vacuo. The product is dissolved in methylenedichloride (100 ml) and washed with 100 ml of dilute ammonium hydroxide; the organic layer is dried over MgSO4 and evaporated in vacuo to give 7,8-dihydro-1,3-dimethyl-1H-imdazo[1,2-c]pyrazolo[3,4-e]pyrimidine 1.5 hydrate, mp 80°-82° C. from ethyl acetate-pet ether.

1. customThe mixture is evaporated in vacuo
2. dissolutionThe product is dissolved in methylenedichloride (100 ml)
3. washwashed with 100 ml of dilute ammonium hydroxide
4. dry with materialthe organic layer is dried over MgSO4
5. customevaporated in vacuo