Hydrochloric Acid → 2,2-Difluoro-benzo(1,3)dioxole-4-carbaldehyde
Reaction equation
Br[CH2:2][C:3]1[C:11]2[O:10][C:9]([F:13])([F:12])[O:8][C:7]=2[CH:6]=[CH:5][CH:4]=1.C1N2CN3CN(C2)CN1C3.Cl.[OH2:25]>>[F:12][C:9]1([F:13])[O:8][C:7]2[CH:6]=[CH:5][CH:4]=[C:3]([CH:2]=[O:25])[C:11]=2[O:10]1Participants
5
Procedure
117 g of crude 4-bromomethyl-2,2-difluoro-1,3-benzodioxole are added to 120 g of urotropin in 250 ml of water and the mixture is heated under reflux for 3 hours. 120 ml of hydrochloric acid in 150 ml of water are then added and the mixture is heated for a further 3 hours. The crude product is then driven over with steam, removed from the receiver and shaken with 100 g of sodium bisulphate in 250 ml of water. After extraction with methylene chloride, the aqueous phase is acidified with 2N sulphuric acid and the aldehyde is separated off and distilled. The yield is 53 g.