Water → 2-chloro-10,11-dihydro-5H-dibenzo-[a,d]cyclohepten-5-ylideneacetic acid ethyl ester

HRID 67639Notes

Reaction equation

HRID 67639 reaction equation
C[C:2](P(OC)(O)=O)([C:4]([O-:6])=[O:5])[CH3:3].[H-].[Na+].[Cl:14][C:15]1[CH:30]=[CH:29][C:18]2C(=O)[C:20]3[CH:27]=[CH:26][CH:25]=[CH:24][C:21]=3[CH2:22][CH2:23][C:17]=2[CH:16]=1.O.O1CC[CH2:34][CH2:33]1>>[CH2:33]([O:6][C:4](=[O:5])[CH:2]=[C:3]1[C:18]2[CH:29]=[CH:30][C:15]([Cl:14])=[CH:16][C:17]=2[CH2:23][CH2:22][C:21]2[CH:20]=[CH:27][CH:26]=[CH:25][C:24]1=2)[CH3:34]

Participants

6

Reactant 5

HCID 962WaterHCID 8028Tetrahydrofuran2×HCID 24758Sodium hydrideHCID 99211482-chloro-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-oneHCID 53413272Trimethylphosphonoacetate

Product 1

HCID 544256632-chloro-10,11-dihydro-5H-dibenzo-[a,d]cyclohepten-5-ylideneacetic acid ethyl ester

Procedure

Trimethylphosphonoacetate (0.53 mole) is added dropwise with stirring to a suspension of sodium hydride (0.48 mole, 50% dispersion in oil) in 250 ml of tetrahydrofuran at 30°-35° C. After the addition, the reaction is stirred for one hr at 20°-30° C. To this reaction mixture, 2-chloro-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-one[0.16 mole, described by S. O. Winthrop, et al., J. Org. Chem., 27, 230 (1962)] in 400 ml of tetrahydrofuran is added. After refluxing for 20 hr the red colored solution is cooled to 0° to 5° C. and water is added dropwise. The aqueous solution is evaporated to remove most of the tetrahydrofuran and extracted with ethyl acetate. The organic phase is dried over magnesium sulfate and evaporated. The residue is subjected to chromatography on silica gel using benzene-hexane (1:1) and the eluates are evaporated to give 2-chloro-10,11-dihydro-5H-dibenzo-[a,d]cyclohepten-5-ylideneacetic acid ethyl ester. The latter compound (11.0 g) is dissolved in ethanol (110 ml) and the solution is added to 10% aqueous potassium hydroxide (110 ml). The resulting solution is refluxed for 3 hr. After the removal of the ethanol by evaporation, the aqueous phase is washed with diethyl ether, adjusted to pH 2 with conc. hydrochloric acid and extracted with chloroform. The chloroform extract is washed with water, dried over magnesium sulfate and evaporated. The residue is crystallized from diethyl ether-hexane to give the title compound as crystals, mp 155°-175° C.

Workup

  1. additionAfter the addition
  2. temperatureAfter refluxing for 20 hr the red colored solution
  3. temperatureis cooled to 0° to 5° C.
  4. customThe aqueous solution is evaporated
  5. customto remove most of the tetrahydrofuran
  6. extractionextracted with ethyl acetate
  7. dry with materialThe organic phase is dried over magnesium sulfate
  8. customevaporated
  9. customthe eluates are evaporated

Sources & evidence

ORD record
ord-e334f7cdc0564eb89ccd7ff528e70c83
Source dataset
uspto-grants-1982_08
Patent number
US04346090

Reaction notes

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