反应详情

A mixture of 28.4 parts of 3-ethyl-1-(4-nitrophenyl)-2,4(1H,3H)-pyrimidinedione, 5 parts of a solution of thiophene in methanol 4% and 500 parts of 2-methoxyethanol was hydrogenated at normal pressure and at 50° C. with 3 parts of platinum-on-charcoal catalyst 5%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was concentrated to a volume of about 150 parts. After cooling, the product was filtered off (the filtrate was set aside) and dried in vacuo at 60° C., yielding a first fraction of 16.5 parts of 1-(4-aminophenyl)-3-ethyl-2,4(1H,3H)-pyrimidinedione (int. 25). The filtrate, which was set aside (see above), was evaporated. The residue was stirred in methanol. The product was filtered off and dried in vacuo at 60° C., yielding a second fraction of 5.7 parts of int. 20. Total yield: 22.2 parts (88.3%) of int. 25; mp. 190.8° C.

1. filtrationthe catalyst was filtered off
2. concentrationthe filtrate was concentrated to a volume of about 150 parts
3. temperatureAfter cooling
4. filtrationthe product was filtered off (the filtrate
5. customdried in vacuo at 60° C.