Potassium Hydroxide → 4-(4-Acetylphenyl)-1,2,4-triazolidine-3,5-dione
Reaction equation
[C:1]([C:4]1[CH:9]=[CH:8][C:7]([NH:10][C:11](=[O:19])[NH:12][NH:13][C:14](OCC)=[O:15])=[CH:6][CH:5]=1)(=[O:3])[CH3:2].[OH-].[K+]>>[C:1]([C:4]1[CH:5]=[CH:6][C:7]([N:10]2[C:11](=[O:19])[NH:12][NH:13][C:14]2=[O:15])=[CH:8][CH:9]=1)(=[O:3])[CH3:2]Participants
3
Procedure
p-Acetyl-4-phenyl-1-carbethoxysemicarbazide 1 (15 g, 56 mmol) was heated with aqueous 4 M KOH solution (28 mL, 112 mmol) at 70° C. for about 2 h. Leftover granular solid was filtered off using a sintered filter funnel. Filtrate was cooled to room temperature and acidified with concentrated HCl. The precipitate formed was filtered and dried in vacuum oven to give p-acetyl-4-phenylurazole 2 as light yellow solid (12.4 g, 85%). 1H NMR (400 MHz, DMSO-d6): s=1.65 (s, 3H), 6.70 (d, 2H), 7.10 (d, 2H), 9.50 (s, 2H). (Synthesis adopted from: Organic Syntheses, Coll. Vol. 6, p. 936 (1988); Vol. 51, p. 121 (1971). 4-PHENYL-1,2,4-TRIAZOLINE-3,5-DIONE). In various aspects, the values of each of the components used in this example can be increased or decreased by an amount in the range of from about 5% to about 20%, for example, each component can be used in an amount that is from 5% less to 5% more than the value used in this example, each component can be used in an amount that is from 10% less to 10% more than the value used in this example, each component can be used in an amount that is from 15% less to 15% more than the value used in this example, or each component can be used in an amount that is from 20% less to 20% more than the value used in this example. In various aspects, the values can be varied by about plus or minus 5% to 20%.