2,2,5-Trimethyl-1,3-dioxane-4,6-dione → 5-(2-Bromo-4-fluoro-phenylazo)-2,2,5-trimethyl-[1,3]dioxane-4,6-dione
Reaction equation
[Br:1][C:2]1[CH:8]=[C:7]([F:9])[CH:6]=[CH:5][C:3]=1[NH2:4].[N:10]([O-])=O.[Na+].[CH3:14][C:15]1([CH3:24])[O:20][C:19](=[O:21])[CH:18]([CH3:22])[C:17](=[O:23])[O:16]1.C([O-])(=O)C.[Na+]>Cl.O.C(O)C>[Br:1][C:2]1[CH:8]=[C:7]([F:9])[CH:6]=[CH:5][C:3]=1[N:4]=[N:10][C:18]1([CH3:22])[C:17](=[O:23])[O:16][C:15]([CH3:14])([CH3:24])[O:20][C:19]1=[O:21]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 3
Procedure
130 g 2-Bromo-4-fluoro-aniline was dissolved in 700 ml ice and 600 ml 3M hydrochloric acid. The resulting suspension was maintained at ca. 5° C. during the addition of a solution of 47.3 g sodium nitrite in 45 ml water. When the addition was complete, the mixture was stirred 45 min at ca 5° C. The resulting brown suspension was added slowly to a cooled mixture of 108.3 g 2,2,5-trimethyl-1,3-dioxan-4,6-dione and 932 g sodium acetate in 400 ml water and 700 ml ethanol, maintaining the temperature between 3 and 8° C. A yellow precipitate formed. The mixture was stirred a further 2 h at 3-8° C., filtered and the precipitate washed with water and dried under vacuum to afford the title compound as a yellow solid. ISP-MS: m/e 359 ([M+H]+). Yield 231 g, mp 92-93° C.
Workup
- additionWhen the addition
- temperaturemaintaining the temperature between 3 and 8° C
- customA yellow precipitate formed
- stirringThe mixture was stirred a further 2 h at 3-8° C.
- filtrationfiltered
- washthe precipitate washed with water
- customdried under vacuum
Sources & evidence
- ORD record
- ord-d8e3e360567946228d294d3176838317
- Source dataset
- uspto-grants-2005_01
- Patent number
- US06844345B2
Reaction notes
Loading…