Boron Trichloride → HCID 21163141, compound

HRID 1278266Notes

Reaction equation

HRID 1278266 reaction equation
C([O:8][C:9]1[CH:26]=[CH:25][C:12]2[C:13](=[O:24])[CH:14]=[C:15]([CH:17]=[CH:18][C:19]([O:21][CH2:22][CH3:23])=[O:20])[O:16][C:11]=2[C:10]=1[CH2:27][CH2:28][CH3:29])C1C=CC=CC=1.B(Cl)(Cl)Cl>ClCCl>[OH:8][C:9]1[CH:26]=[CH:25][C:12]2[C:13](=[O:24])[CH:14]=[C:15](/[CH:17]=[CH:18]/[C:19]([O:21][CH2:22][CH3:23])=[O:20])[O:16][C:11]=2[C:10]=1[CH2:27][CH2:28][CH3:29]

Participants

4

Reactant 2

HCID 25135Boron TrichlorideHCID 54194018HCID 54194018, compound

Product 1

HCID 21163141HCID 21163141, compoundYield 69.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of ethyl 3-(7-benzyloxy-4-oxo-8-n-propyl-4H-1-benzopyran-2-yl)acrylate (6.0 g) in dichloromethane (150 ml) at -60° C. was treated with an excess of BCl3. After 3/4 hour the solution was poured onto ice and stirred. After 12 hours the mixture was extracted with ethyl acetate. The organic layer was separated, washed well (water), dried (MgSO4) and evaporated to afford a pale yellow solid. The latter was crystallised from aqueous ethanol to yield trans ethyl 3-(7-hydroxy-4-oxo-8-n-propyl-4H-1-benzopyran-2-yl)acrylate (3.2 g) mp 203°-204° C.

Workup

  1. additionAfter 3/4 hour the solution was poured onto ice
  2. extractionAfter 12 hours the mixture was extracted with ethyl acetate
  3. customThe organic layer was separated
  4. washwashed well (water)
  5. dry with materialdried (MgSO4)
  6. customevaporated
  7. customto afford a pale yellow solid
  8. customThe latter was crystallised from aqueous ethanol

Sources & evidence

ORD record
ord-853b50af23e944aa9bb46fcdbca9a768
Source dataset
uspto-grants-1981_07
Patent number
US04281008

Reaction notes

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