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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2232479Generated: October 31, 2026

Allyl bromide → racemic-3,4-dihydro-2,5,7,8-tetramethyl-6-(2-propenyloxy)-2H-1-benzopyran-2-acetic acid methyl ester

https://huagongshe.com/reaction/2232479

Reaction equation

Participants

RoleNameHCIDCharge
ReactantAllyl bromideHCID 7841—
ReactantSodium hydrideHCID 24758—
ReactantMethyl 6-hydroxy-2,5,7,8-tetramethylchroman-2-acetateHCID 13909413—
SolventDimethylformamideHCID 6228—
Productracemic-3,4-dihydro-2,5,7,8-tetramethyl-6-(2-propenyloxy)-2H-1-benzopyran-2-acetic acid methyl esterHCID 5401205883.1%

Reaction Steps

Using the procedure of Example 12, 1.42 g of racemic-3,4-dihydro-2,5,7,8-tetramethyl-6-hydroxy-2H-1-benzopyran-2-acetic acid methyl ester was alkylated with allyl bromide (2.79 g) and sodium hydride (5.58 mmole) in anhydrous N,N-dimethylformamide. There was obtained 1.35 g (83.1%) of racemic-3,4-dihydro-2,5,7,8-tetramethyl-6-(2-propenyloxy)-2H-1-benzopyran-2-acetic acid methyl ester as a yellow oil, after column chromatographic purification (silica gel, 9:1 hexane-ethyl acetate).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS04788214
Source datasetuspto-grants-1988_11
ORD IDord-6ab63fb4d06d4c009bd49b1b98a6b835
Source noteuspto-grants-1988_11