Methyl triflate → 4-Acetylthiomethylthio-3-methyl-1,2,3-triazole

To a solution of 4-acetylthiomethylthio-1,2,3-triazole (6 g : 31.75 mMol.) in tetrahydrofuran (30 ml) is added dropwise at -78° C. a solution of 1M lithium bis(trimethylsilyl)amide in tetrahydrofuran (35 ml : 35 mMol.), and the mixture is stirred at the same temperature for 5 minutes and added methyl trifluoromethanesulfonate (4.0 ml : 35 mMol.). After stirring at the same temperature for 2 hours, the reaction mixture is diluted with 10% hydrochloric acid (26 ml) and water, and extracted with ethyl acetate. The extract is washed with aqueous sodium hydrogen carbonate and brine, dried over sodium sulfate, and concentrated. The residue is purified by silica gel chromatography (n-hexane : ethyl acetate=1:2) to give 4-acetylthiomethylthio-3-methyl-1,2,3-triazole 2.22 g; NMR δ (CDCl3) ppm: 2.32(s, 3H). 4.13(s, 5H). 7.77(s, 1H).IR ν (CHCl3) cm-1 : 1698, 1429, 1355, 1263, 1226, 1205, 1127, 1100, 957. mp. 37°-38° C. Yield: 34%, 4-acetylthiomethylthio-1-methyl-1,2,3- triazole [884 mg; NMR δ (CDC13) ppm: 2.35(s, 3H), 4.11(s, 3H), 4.33(s, 2H), 7.59(s, 1H).IR (CHC13) cm-1 : 1691, 1434, 1354, 1285, 1131, 1106, 1048, 1031, 956.mp. 71°-72° C. Yield: 14%], and 4-acetylthiomethylthio-2-methyl-1,2,3-triazole [175 mg; NMR δ (CDC13) ppm: 2.35 (s, 3H), 4.20(s, 3H), 4.30(s,2H), 7.56(s, 1H).IR (CHCl3) cm-1 : 1691, 1446, 1369, 1130, 1006, 990, 956.Oil. Yield: 3%].

1. stirringAfter stirring at the same temperature for 2 hours
2. extractionextracted with ethyl acetate
3. washThe extract is washed with aqueous sodium hydrogen carbonate and brine
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated
6. customThe residue is purified by silica gel chromatography (n-hexane : ethyl acetate=1:2)

ORD record

ord-7e3cd510d1054b449148d80d4b8a3b5f

Source dataset

uspto-grants-1993_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05214037