Benzene → Chroman

HRID 568724Notes

Reaction equation

HRID 568724 reaction equation
[N-]=C=S.C(Cl)Cl.Cl[CH:8](Cl)[CH3:9].[CH:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.[CH3:17][OH:18]>>[O:18]1[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=2[CH2:9][CH2:8][CH2:17]1

Participants

6

Reactant 5

HCID 241BenzeneHCID 887MethanolHCID 6344DichloromethaneHCID 63651,1-DichloroethaneHCID 178418790HCID 178418790, compound

Product 1

HCID 136319Chroman

Procedure

Thus, a known alcohol of general formula (V-1) is reacted with an organic sulfonyl chloride in the presence of pyridine in the conventional manner to give a sulfonic acid ester of general formula (VI-1) and this sulfonic acid ester is then reacted with potassium phthalimide to give an N-substituted phthalimide of general formula (VII), which is further treated with hydrazine to give an amine of general formula (VIII). This amine of general formula (VIII) is reacted with 0.9 to 1.1 molar equivalents of an isothiocyanate in an inert solvent such as methylene chloride, dichloroethane, benzene, methanol, etc. at a temperature of room temperature to reflux temperature to give a 3,4-dihydrobenzopyran derivative of general formula (I-1b). And the amine of general formula (VIII) is reacted with 0.9 to 1.2 molar equivalents of methylisothiourea in an inert solvent such as methanol, ethanol, etc. at a temperature of room temperature to reflux temperature to give a 3,4-dihydrobenzopyran derivative of general formula (I-1c). The separation and purification of 3,4-dihydrobenzopyran derivative (I-1b) or 3,4-dihydrobenzopyran derivative (I-1c) from the reaction mixture can be carried out in the conventional manner.

Workup

  1. temperatureto reflux temperature

Sources & evidence

ORD record
ord-6e557c1ff2b54700be5a9b6d6b15abe4
Source dataset
uspto-grants-1988_03
Patent number
US04728650

Reaction notes

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