N-bromobutanimide → 2,2-Dicarbethoxy-1-(3',4',5'-trimethoxyphenyl)-6,7-methylenedioxy-4-tetralone

HRID 1112555Notes

Reaction equation

HRID 1112555 reaction equation
[C:1]([C:6]1([C:31]([O:33][CH2:34][CH3:35])=[O:32])[CH2:15][CH2:14][C:13]2[C:8](=[CH:9][C:10]3[O:18][CH2:17][O:16][C:11]=3[CH:12]=2)[CH:7]1[C:19]1[CH:24]=[C:23]([O:25][CH3:26])[C:22]([O:27][CH3:28])=[C:21]([O:29][CH3:30])[CH:20]=1)([O:3][CH2:4][CH3:5])=[O:2].BrN1C(=[O:42])CCC1=O>>[C:31]([C:6]1([C:1]([O:3][CH2:4][CH3:5])=[O:2])[CH2:15][C:14](=[O:42])[C:13]2[C:8](=[CH:9][C:10]3[O:18][CH2:17][O:16][C:11]=3[CH:12]=2)[CH:7]1[C:19]1[CH:24]=[C:23]([O:25][CH3:26])[C:22]([O:27][CH3:28])=[C:21]([O:29][CH3:30])[CH:20]=1)([O:33][CH2:34][CH3:35])=[O:32]

Participants

3

Reactant 2

HCID 67184N-bromobutanimideHCID 227636672,2-Dicarbethoxy-1-(3',4',5'-trimethoxyphenyl)-6,7-methylenedioxytetralin

Product 1

HCID 127742932,2-Dicarbethoxy-1-(3',4',5'-trimethoxyphenyl)-6,7-methylenedioxy-4-tetralone

Procedure

In a small Pyrex tube equipped with a spin bar was added 50 mg of 2,2-dicarbethoxy-1-(3',4',5'-trimethoxyphenyl)-6,7-methylenedioxytetralin (XIV-b; R2 = ethyl) and 72 mg (4.0 eq) of N-bromosuccinimide (recrystallized from water). Dioxane (2 ml) was distilled in (from (Na/benzophenone), and the tube was sealed and placed under nitrogen. The mixture was irradiated for 2 min with a sunlamp while cooling with a cold water stream. Water (+μl) was then syringed in and irradiation and cooling was maintained for 18 to 20 min. The reaction mixture was then poured into saturated sodium bisulfite and extracted three times with chloroform. The organic layer was washed twice with 2N sodium hydroxide, twice with water, once with saturated brine, and was dried over sodium sulfate. Filtration and evaporation gave the title product (XV; R2 = ethyl) plus the ring bromination product at C-2' (<10%). One crystallization from methanol gave 46 mg (90%) pure title product, mp 152°-153°.

Workup

  1. customIn a small Pyrex tube equipped with a spin bar
  2. distillationDioxane (2 ml) was distilled in (from (Na/benzophenone)
  3. customthe tube was sealed
  4. customThe mixture was irradiated for 2 min with a sunlamp
  5. temperaturewhile cooling with a cold water stream
  6. customirradiation
  7. temperaturecooling
  8. temperaturewas maintained for 18 to 20 min
  9. additionThe reaction mixture was then poured into saturated sodium bisulfite
  10. extractionextracted three times with chloroform
  11. washThe organic layer was washed twice with 2N sodium hydroxide, twice with water, once with saturated brine
  12. dry with materialwas dried over sodium sulfate
  13. filtrationFiltration and evaporation

Sources & evidence

ORD record
ord-b3b54366609e4e44871123aa7a0e8723
Source dataset
uspto-grants-1978_10
Patent number
US04122092

Reaction notes

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