Potassium Hydroxide → HCID 23669974, compound

HRID 2419474Notes

Reaction equation

HRID 2419474 reaction equation
C[O:2][C:3]([C:5]1[O:10][C:9]2[C:11]3[CH:18]=[CH:17][CH:16]=[CH:15][C:12]=3[O:13][CH2:14][C:8]=2[C:7](=[O:19])[CH:6]=1)=[O:4].[OH-].[K+:21]>CO>[K+:21].[O:19]=[C:7]1[CH:6]=[C:5]([C:3]([O-:4])=[O:2])[O:10][C:9]2[C:11]3[CH:18]=[CH:17][CH:16]=[CH:15][C:12]=3[O:13][CH2:14][C:8]1=2

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 126777564-Oxo-4H, 5H-[1]benzopyrano [4,3-b]pyran-2-carboxylic Acid Methyl Ester

Product 1

HCID 23669974HCID 23669974, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 4-oxo-4H,5H-[1]benzopyrano[4,3-b]pyran-2-carboxylic acid methyl ester (0.292 g, 1.1 moles, described in Example 6) in methanol (15 ml) containing potassium hydroxide (0.2 g) is stirred at room temperature overnight. The solution is evaporated under reduced pressure and the residue is crystallized from methanol to give 4-oxo-4H,5H-[1]benzopyrano[4,3-b]pyran-2-carboxylic acid potassium salt; m.p. > 280° C, νmaxnujol 1650 cm-1. The latter compound is dissolved in water and the resulting solution is added to dilute hydrochloric acid. The precipitate is collected and crystallized from methanol to give the title compound; m.p. 253°-254° C (dec.), νmaxnujol 2500, 1735 and 1650 cm-1.

Workup

  1. customThe solution is evaporated under reduced pressure
  2. customthe residue is crystallized from methanol

Sources & evidence

ORD record
ord-86972fbeea474eae99813c5c0988accf
Source dataset
uspto-grants-1978_08
Patent number
US04105778

Reaction notes

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