2,2-Dimethoxy-2-phenylacetophenone → Phenyl(2-phenyl-4,7-dihydro-2H-1,3-dioxepin-2-yl)methanone

HRID 1980198Notes

Reaction equation

HRID 1980198 reaction equation
[CH3:1][O:2][C:3]([O:18][CH3:19])([C:10]([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:11])[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.[CH2:20](O)/[CH:21]=C\CO>C1(C)C=CC(S(O)(=O)=O)=CC=1>[C:10]([C:3]1([C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=2)[O:2][CH2:1][CH:21]=[CH:20][CH2:19][O:18]1)(=[O:11])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

4

Reactant 2

HCID 905712,2-Dimethoxy-2-phenylacetophenoneHCID 6437902-Butene-1,4-diol, (2Z)-

Product 1

HCID 22163341Phenyl(2-phenyl-4,7-dihydro-2H-1,3-dioxepin-2-yl)methanoneYield 96%

Reagents, catalysts & solvents 1

HCID 6101p-Toluenesulfonic acidCatalyst

Procedure

1 g of p-toluene sulphonic acid was added to a suspension of 77 g (0.3 mols) of benzil dimethyl ketal in 160 g (~1.8 mols) of cis-2-butene-1,4-diol, and heated to from 50° to 60° C. under a pressure of from 10 to 15 torr. After 45 minutes, a clear solution was obtained, the temperature of which rose to from 65° to 70° C. After a further 45 minutes, the reaction mixture had solidified into a crystal mass. After a total of 4 hours, the material was recrystallized from isopropanol, and 80 g (96%) of 2-benzoyl-2-phenyl-4,7-dihydro-1,3-dioxepin were obtained as colourless crystals having a melting point of from 118° to 119° C.

Workup

  1. temperatureheated to from 50° to 60° C. under a pressure of from 10 to 15 torr
  2. customa clear solution was obtained
  3. customrose to from 65° to 70° C
  4. waitAfter a further 45 minutes
  5. customAfter a total of 4 hours, the material was recrystallized from isopropanol

Sources & evidence

ORD record
ord-a3fc4902f505402f957c2ce75d81467d
Source dataset
uspto-grants-1984_11
Patent number
US04485249

Reaction notes

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