Hydrochloric Acid → 5,5-Bis(3,5-difluorophenyl)-2,4-imidazolidinedione

HRID 1607437Notes

Reaction equation

[F:1][C:2]1[CH:3]=[C:4]([CH:15]=[C:16]([F:18])[CH:17]=1)[C:5]([C:7]1[CH:12]=[C:11]([F:13])[CH:10]=[C:9]([F:14])[CH:8]=1)=O.[C-:19]#[N:20].[K+].[C:22](=[O:25])([O-])[O-].[NH4+:26].[NH4+].Cl.[OH2:29]>C(O)C>[F:1][C:2]1[CH:3]=[C:4]([C:5]2([C:7]3[CH:12]=[C:11]([F:13])[CH:10]=[C:9]([F:14])[CH:8]=3)[NH:26][C:19](=[O:29])[NH:20][C:22]2=[O:25])[CH:15]=[C:16]([F:18])[CH:17]=1

Participants

Conditions

Temperature: 115 °C

Procedure

A mixture of 3,3',5,5'-tetrafluorobenzophenone (358 g, 1.41 mol), potassium cyanide (137.5 g, 2.11 mol), ammonium carbonate (406 g, 4.22 mol) and ethanol (3.5 L) was heated at 115° C. for 16 h in a stirred 2 gal pressure reactor. After chilling to relieve the pressure, the reactor was opened and the mixture was poured into 8 L of water in a 22-L flask equipped with a mechanical stirrer. The mixture was acidified (pH 2.0) using concentrated hydrochloric acid (~1 L) (Note 1) and the resulting precipitate was collected by filtration, washed with water, and pressed dry. The crude material was recrystallized from ethanol (~6 L) to provide 399.5 g (87%) of 5,5-di(3,5-difluorophenyl)-2,4-imidazolidinedione (Note 2): mp 271°-274° C.; MS m/z 324 (M+); 1H NMR (DMSO-d6) δ 9.50 (s, 2); 7.42-6.90 (m, 6); IR (KBr) 3265, 3160, 3060, 1762, 1710 cm-1.

Workup

temperatureAfter chilling
customequipped with a mechanical stirrer
filtrationthe resulting precipitate was collected by filtration
washwashed with water
custompressed dry
customThe crude material was recrystallized from ethanol (~6 L)

Sources & evidence

ORD record: ord-0abe7935514b47d8806134368a9b07d2
Source dataset: uspto-grants-1989_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04864028

Reaction notes

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