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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1657479Generated: November 1, 2026

Hydrochloric Acid → 8-methoxy-1-oxo-1H-2-benzothiopyran-3-carboxylic acid

https://huagongshe.com/reaction/1657479

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
ReactantSodium HydroxideHCID 14798—
Reactant5-(2-Carboxy-3-methoxybenzylidene)rhodanineHCID 54306741—
Product8-methoxy-1-oxo-1H-2-benzothiopyran-3-carboxylic acidHCID 21440750—

Reaction Steps

A solution of the benzylidenerhodanine of Example 10 in 46 ml. of 15% NaOH is refluxed for 0.75 hour, cooled, and poured into dilute HCl. The resulting tan precipitate is collected and air-dried. Two recrystallizations from methanol (charcoal) give 8-methoxy-1-oxo-1H-2-benzothiopyran-3-carboxylic acid as a pale yellow solid, m.p. 275° (dec.).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS03960892
Source datasetuspto-grants-1976_06
ORD IDord-53f3d0244d5d4b08a6e26f6828b8769e
Source noteuspto-grants-1976_06