[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]=1[C:8]#[N:9].[N-:19]=[N+:20]=[N-:21].[Na+].[Cl-].[NH4+]>CN(C)C=O>[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]=1[C:8]1[NH:21][N:20]=[N:19][N:9]=1A mixture of 3-methyl-4-oxo-4H,5H-[1]benzothiopyrano[4,3-b]pyran-2-carbonitrile (3.14 g, 12.3 mmoles, described in Example 6), sodium azide (0.884 g, 13.6 mmoles) and ammonium chloride (0.130 g, 2.4 mmoles) in dimethylformamide (18 ml) is heated at 110° C. for 18 hr. The dark solution is evaporated and the residue is dissolved in water (50 ml). The aqueous solution is washed with ethyl acetate and acidified with 10% hydrochloric acid. The precipitate is collected, washed with water and crystallized from acetone-water to give the title compound (2.5 g), mp 247°-248° C.
Loading…
