Hydrochloric Acid → HCID 12197347, compound

HRID 1074461Notes

Reaction equation

HRID 1074461 reaction equation
[OH:1][C:2]1[CH:13]=[CH:12][C:5]2[C:6](=O)[CH:7]=[C:8]([CH3:10])[O:9][C:4]=2[CH:3]=1.O.Cl.CO>N1C=CC=CC=1.C(OC(=O)C)(=O)C>[OH:1][C:2]1[CH:13]=[CH:12][C:5]2[CH2:6][CH2:7][CH:8]([CH3:10])[O:9][C:4]=2[CH:3]=1

Participants

7

Reactant 4

HCID 313Hydrochloric Acid2×HCID 887MethanolHCID 962WaterHCID 53553097-hydroxy-2-methyl-4H-1-benzopyran-4-one

Product 1

HCID 12197347HCID 12197347, compoundYield 71.2%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 7918Acetic AnhydrideSolvent

Procedure

9.8 g 7-hydroxy-2-methyl-4H-1-benzopyrane-4-on in 20 cm3 dry pyridine and 20 cm3 acetic anhydride was left to stand for 24 hours. The obtained solution was admixed with the mixture of ice, water and hydrochloric acid and the precipitate [11 g of 7-acetoxy-2-methyl-4H-1-benzopyrane-4-on, m.p. 94°-95° C. from benzene] was filtered. The acetoxy compound was hydrogenated in glacial acetic acid at 60° C. in the presence of a palladium on charcoal catalyst till it absorbed 3 molar equivalents of hydrogen, then after filtration and evaporation 11.5 g 7-acetoxy-2-methyl-3,4-dihydro-2H-1-benzopyrane-4-on (m.p. 66°-68° C. from ethanol) was obtained. This compound was hydrolyzed hot in the mixture of 100 cm3 methanol and 1.5 cm3 concentrated hydrochloric acid. The solvent was distilled off, the residue was subjected to fractionated distillation to obtain 6.5 g 7-hydroxy-2-methyl-3,4-dihydro-2H-1-benzopyrane (b.p. 85°-90° C./26 Pa); starting from this compound and following the process of example 5 (b), using a piperidine catalyst and 1-chloro-2,3-epoxypropane reagent, 1-chloro-3-(2-methyl-3,4-dihydro-2H-1-benzopyrane-7-yloxy)-2-propanol (m.p. 70°-72° C.) was obtained.

Workup

  1. filtrationthe precipitate [11 g of 7-acetoxy-2-methyl-4H-1-benzopyrane-4-on, m.p. 94°-95° C. from benzene] was filtered
  2. customwas hydrogenated in glacial acetic acid at 60° C. in the presence of a palladium on charcoal catalyst till it
  3. customabsorbed 3 molar equivalents of hydrogen
  4. filtrationafter filtration
  5. customevaporation 11.5 g 7-acetoxy-2-methyl-3,4-dihydro-2H-1-benzopyrane-4-on (m.p. 66°-68° C. from ethanol)
  6. customwas obtained
  7. distillationThe solvent was distilled off
  8. distillationthe residue was subjected to fractionated distillation

Sources & evidence

ORD record
ord-519e90ae9df34e07af83649959f5ad9e
Source dataset
uspto-grants-1983_07
Patent number
US04391821

Reaction notes

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