Diisopropylamine → methyl 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)acrylate

HRID 329328Notes

Reaction equation

HRID 329328 reaction equation
[CH2:1]([Li])CCC.C(NC(C)C)(C)C.O1CCCC1.[O:18]=[C:19]1[C:25]2[CH:26]=[CH:27][C:28]([CH2:30][C:31]([O:33][CH3:34])=[O:32])=[CH:29][C:24]=2[CH:23]=[CH:22][C:21]2[CH:35]=[CH:36][CH:37]=[CH:38][C:20]1=2>CCCCCC.CN(C)P(=O)(N(C)C)N(C)C>[O:18]=[C:19]1[C:25]2[CH:26]=[CH:27][C:28]([C:30](=[CH2:1])[C:31]([O:33][CH3:34])=[O:32])=[CH:29][C:24]=2[CH:23]=[CH:22][C:21]2[CH:35]=[CH:36][CH:37]=[CH:38][C:20]1=2

Participants

7

Reactant 4

HCID 7912DiisopropylamineHCID 8028TetrahydrofuranHCID 12398824HCID 12398824, compoundHCID 178418339Butyllithium

Product 1

HCID 12398832methyl 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)acrylate

Reagents, catalysts & solvents 2

HCID 8058HexaneSolventHCID 12679HexamethylphosphoramideSolvent

Conditions

Temperature
-80 °C

Procedure

1.25 Ml. of 1.6 molar n-butyllithium in hexane is added to a solution of 0.280 ml. of diisopropylamine in 30 ml. of tetrahydrofuran. The solution is cooled to -80° C and 0.556 g. of methyl (5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)acetate is added. After 10 minutes 0.38 ml. of hexamethylphosphoric triamide is added. The cooling bath is removed and formaldehyde vapor, entrained in nitrogen, is passed over the solution until it becomes colorless. Water and ether are then added and the organic layer is washed with dilute hydrochloric acid, saturated sodium chloride solution, then dried and evaporated. The residue is chromatographed on 10 g. of silica gel, eluting with hexane: ethyl acetate (5:1) to isolate methyl 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)acrylate (m.p. 153°-156° C). 0.02 G. of this compound is refluxed under nitrogen in 5 ml. of water, 2 ml. of ethanol and 0.5 ml. of saturated sodium carbonate solution for 4 hours. The mixture is cooled, washed with ether and acidified with dilute hydrochloric acid, then extracted with ethyl acetate and the extract dried and evaporated to yield 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2yl)acrylic acid (m.p. 232°-235° C).

Workup

  1. customThe cooling bath is removed
  2. additionWater and ether are then added
  3. washthe organic layer is washed with dilute hydrochloric acid, saturated sodium chloride solution
  4. customdried
  5. customevaporated
  6. customThe residue is chromatographed on 10 g
  7. washof silica gel, eluting with hexane: ethyl acetate (5:1)

Sources & evidence

ORD record
ord-5a36e58304114195af9d8814ec667d19
Source dataset
uspto-grants-1977_04
Patent number
US04020094

Reaction notes

Loading…