Hydrochloric Acid → 6,11-Dihydro-11-oxodibenz[b,e]oxepin-2-propanoic acid

HRID 580048Notes

Reaction equation

HRID 580048 reaction equation
[C:1]([C:4]1[CH:22]=[CH:21][CH:20]=[CH:19][C:5]=1[CH2:6][O:7][C:8]1[CH:13]=[CH:12][C:11]([CH:14]([CH3:18])C(O)=O)=[CH:10][CH:9]=1)([OH:3])=O.ClCCl.FC(F)(F)[C:28]([O:30]C(=O)C(F)(F)F)=[O:29].Cl>O>[O:3]=[C:1]1[C:4]2[CH:22]=[CH:21][CH:20]=[CH:19][C:5]=2[CH2:6][O:7][C:8]2[CH:9]=[CH:10][C:11]([CH2:14][CH2:18][C:28]([OH:30])=[O:29])=[CH:12][C:13]1=2

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6344DichloromethaneHCID 9845Trifluoroacetic anhydrideHCID 122923134-(2-Carboxybenzyloxy)phenylpropanoic acid

Product 1

HCID 123929606,11-Dihydro-11-oxodibenz[b,e]oxepin-2-propanoic acidYield 79.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A stirred suspension of 4-(2-carboxybenzyloxy)phenylpropanoic acid (47.14 g, 0.157 mol) and dichloromethane (500 ml) was treated over 30 seconds with trifluoroacetic anhydride (75.61 g, 0.36 mol). The solid material slowly dissolved. The solution was heated 6 hours under reflux with exclusion of moisture. The cooled solution was treated with water (100 ml) and stirred 20 minutes at ambient temperature (mild exotherm). The mixture was strongly acidified with 5% hydrochloric acid and thoroughly agitated. The organic phase was washed with water (200 ml), dried (Na2SO4) and evaporated to dryness. Recrystallization from 65 ml of isopropanol afforded 35.3 g (79.6%) of 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-propanoic acid, m.p. 138.5°-139.5° C. The compound appeared pure and chromatographically identical with material which had previously been prepared according to procedure 6C below except that it is postulated that the product exists in two polymorphic forms and interconversion by partial melting followed by solidification to afford the higher melting form occurs at 128°-130° C.

Workup

  1. dissolutionThe solid material slowly dissolved
  2. temperatureThe solution was heated 6 hours
  3. temperatureunder reflux with exclusion of moisture
  4. stirringthoroughly agitated
  5. washThe organic phase was washed with water (200 ml)
  6. dry with materialdried (Na2SO4)
  7. customevaporated to dryness
  8. customRecrystallization from 65 ml of isopropanol

Sources & evidence

ORD record
ord-f137d7915bb14d52812b33b5e2d94be3
Source dataset
uspto-grants-1988_06
Patent number
US04751238

Reaction notes

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