反应详情

2-cyano-3,3-bis-methylsulfanyl-acrylic acid methyl ester Compound 1a (25.0 g, 123 mmol) was combined with 97% 2-cyano-thioacetamide (12.7 g, 123 mmol) and K2CO3 (51.0 g, 369 mmol) in DMSO (300 mL) at room temperature. The reaction was stirred for 18 hrs. The cooled reaction mixture (0° C.) was slowly acidified with 1N HCl. The resultant yellow precipitate was collected by filtration and sequentially washed with 1N HCl, water, MeOH and hexane to give 6-hydroxy-4-methylsulfanyl-2-thioxo-1,2-dihydro-pyridine-3,5-dicarbonitrile Compound 1b (24.7 g, 90% yield). 1H NMR (DMSOd6) δ 2.66 (s, 3H). 13C NMR (DMSOd6) δ 118.1 (CN), 117.3 (CN), 17.4 (SMe). MS 222 (M−).

1. customThe cooled reaction mixture (0° C.)
2. filtrationThe resultant yellow precipitate was collected by filtration
3. washsequentially washed with 1N HCl, water, MeOH and hexane