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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 892512Generated: October 31, 2026

Acetic Acid → HCID 19895670, compound

https://huagongshe.com/reaction/892512

Reaction equation

Participants

RoleNameHCIDCharge
ReactantAcetic AcidHCID 176—
ReactantHCID 19895692HCID 19895692—
CatalystPalladiumHCID 23938—
SolventEthanolHCID 702—
ProductHCID 19895670HCID 1989567046.8%

Reaction Steps

2.97 g of 2,2-dimethyl-4-(3-methyl-2-pyridyl)-2H-1-benzopyran were dissolved in 50 ml of ethanol and shaken at room temperature under a hydrogen atmosphere with 10% palladium-on-charcoal in the presence of 0.5 ml of acetic acid. After 24 hours the catalyst was filtered off and the filtrate was evaporated. The residue was chromatographed on silica gel using ethyl acetate/petroleum ether (1:4) for the elution. There were obtained 1.4 g of 3,4-dihydro-2,2-dimethyl-4-(3-methyl-2-pyridyl)-2H-1-benzopyran together with mixed fractions containing this compound and starting material. The procedure described above was carried out on the mixed fractions to give 675 mg of 3,4-dihydro-2,2-dimethyl-4-(3-methyl-2-pyridyl)-2H-1-benzopyran which was recrystallized from t-butyl methyl ether and then melted at 100°-102° C.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS05118694
Source datasetuspto-grants-1992_06
ORD IDord-7eaa6eb285e84619a5406d0f04253c5b
Source noteuspto-grants-1992_06