Methanol → 6-Bromo-3,4-dihydro-2H-1-benzopyran-2-methanol

HRID 1906876Notes

Reaction equation

HRID 1906876 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]([C:11](O)=[O:12])[CH2:8][CH2:7][C:6]=2[CH:14]=1.B.S(C)C.CO>O1CCCC1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]([CH2:11][OH:12])[CH2:8][CH2:7][C:6]=2[CH:14]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 1068Dimethyl SulfideHCID 6331BoraneHCID 223513906-Bromo-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

Product 1

HCID 202110506-Bromo-3,4-dihydro-2H-1-benzopyran-2-methanolYield 86%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a stirred mixture of 80 parts of 6-bromo-3,4-dihydro-2H-benzopyran-2-carboxylic acid and 225 parts of tetrahydrofuran were added dropwise 400 parts of a solution of borane, compound with thiobismethane 0.2N in tetrahydrofuran. Upon completion, stirring was continued for 4hours at room temperature. 80 parts of methanol were added dropwise and stirring was continued for 30 minutes at reflux temperature. The solvent was distilled off till half its volume. The remaining solvent was evaporated and the residue was distilled, yielding 63 parts (86%) of 6-bromo-3,4-dihydro-2H-1-benzopyran-2-methanol; bp. 150° C. at 39.9 Pa (intermediate 1).

Workup

  1. stirringstirring
  2. waitwas continued for 30 minutes
  3. temperatureat reflux temperature
  4. distillationThe solvent was distilled off till half its volume
  5. customThe remaining solvent was evaporated
  6. distillationthe residue was distilled

Sources & evidence

ORD record
ord-00b34106b0ca4ad589a61fd6922c9c6a
Source dataset
uspto-grants-1987_03
Patent number
US04654362

Reaction notes

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