Hydrochloric Acid → HCID 20344235, compound

Reaction equation

[CH3:1][C:2]1[C:3](=[O:18])[C:4]2[CH2:13][S:12][C:11]3[CH:14]=[CH:15][CH:16]=[CH:17][C:10]=3[C:5]=2[O:6][C:7]=1C#N.Cl.[OH-:20].[Na+]>CO>[CH3:1][CH:2]1[C:7](=[O:20])[O:6][C:5]2[C:10]3[CH:17]=[CH:16][CH:15]=[CH:14][C:11]=3[S:12][CH2:13][C:4]=2[C:3]1=[O:18]

Participants

Procedure

A solution of 3-methyl-4-oxo-4H,5H-[1]benzothiopyrano[4,3-b]pyran-2-carbonitrile (0.255 g, 1 mmole, described in Example 6) in 2.5N aqueous sodium hydroxide (10 ml) and methanol (5 ml) is refluxed overnight. The solution is acidified with hydrochloric acid. The precipitate is collected and dissolved in IN aqueous sodium hydroxide. The solution is washed with chloroform and acidified with hydrochloric acid. The precipitate is collected and crystallized from methanol to give the title compound (0.070 g), mp 275°-277° C.