Hydrochloric Acid → HCID 21440739, compound

Reaction equation

[C:1]([C:4]1[CH:17]=[CH:16][CH:15]=[C:14]([O:18][CH3:19])[C:5]=1[CH:6]=[C:7]1[S:11]C(=S)N[C:8]1=[O:13])([OH:3])=O.[OH-:20].[Na+].Cl>>[CH3:19][O:18][C:14]1[C:5]2[CH:6]=[C:7]([C:8]([OH:20])=[O:13])[S:11][C:1](=[O:3])[C:4]=2[CH:17]=[CH:16][CH:15]=1

Participants

Reactant 3

HCID 313Hydrochloric Acid

HCID 14798Sodium Hydroxide

HCID 54339098HCID 54339098, compound

Product 1

HCID 21440739HCID 21440739, compound

Procedure

A solution of 0.6 g. (2 mM) of the benzylidenerhodanine of Example 16 in 10 ml. of 15% NaOH is refluxed under nitrogen for 0.5 hour, cooled, and poured into cold dilute HCl to form a tan precipitate. The solid is collected, washed with water and recrystallized from methanol to give 5-methoxy-1-oxo-1H-2-benzothiopyran-3-carboxylic acid as yellow needles, m.p. 283°-284°.