Hydrochloric Acid → HCID 21440743, compound

HRID 1657473Notes

Reaction equation

HRID 1657473 reaction equation
[C:1]([C:4]1[CH:17]=[CH:16][C:15]([O:18][CH3:19])=[CH:14][C:5]=1[CH:6]=[C:7]1[S:11]C(=S)N[C:8]1=[O:13])([OH:3])=O.Cl.[OH-:21].[Na+]>>[CH3:19][O:18][C:15]1[CH:16]=[CH:17][C:4]2[C:1](=[O:3])[S:11][C:7]([C:8]([OH:21])=[O:13])=[CH:6][C:5]=2[CH:14]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 54533504HCID 54533504, compound

Product 1

HCID 21440743HCID 21440743, compound

Procedure

A solution of the 5-(2-carboxy-5-methoxybenzylidene)-rhodanine of Example 4 in dilute sodium hydroxide (35 ml. of 20% NaOH + 11 ml. H2O) is refluxed for one hour and then poured into dilute HCl. The resulting pale yellow solid is collected and recrystallized repeatedly from ethanol to give 6-methoxy-1-oxo-1H-2-benzothiopyran-3-carboxylic acid as pale yellow crystals, m.p. 278°-279°.

Workup

  1. customThe resulting pale yellow solid is collected
  2. customrecrystallized repeatedly from ethanol

Sources & evidence

ORD record
ord-666ee2711a4d411f9218b12cf682ce75
Source dataset
uspto-grants-1976_06
Patent number
US03960892

Reaction notes

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