Formaldehyde → HCID 178422344, compound

To 2-benzoylthio-6-(tert-butoxycarbonyl)-4,5,6,7-tetrahydropyrido[4,3-d][1,3]thiazole (2.44 g, 6.49 mmol) is gradually added dropwise a mixture of anisole (1.41 ml, 12.98 mmol) and trifluoroacetic acid (10.0 ml, 129.8 mmol) at 0° C., and after the addition, the mixture is warmed to room temperature and stirred for 30 minutes. The reaction solution is concentrated under reduced pressure, and to the resulting residue is added methylene chloride. The mixture is concentrated under reduced pressure again, and the resulting residue is crystallized from ether to give pale yellow crystals. The resulting crystals are suspended in THF (30 ml), and thereto is added a 37% aqueous formaldehyde solution (2.04 g, 25.2 mmol) at room temperature, and then further added thereto a 2N aqueous sodium hydroxide solution. The mixture is stirred for one hour, and thereto is added sodium cyanoborohydride (507 mg, 8.06 mmol), and the mixture is further stirred for additional one hour. To the reaction solution is added iN aqueous hydrochloric acid solution to make it weakly acidic, and the mixture is stirred for 30 minutes. The reaction solution is diluted with ethyl acetate, washed with a saturated aqueous sodium hydrogen carbonate solution, dried over sodium sulfate, and concentrated under reduced pressure. The residue is purified by silica gel column chromatography (methylene chloride/methanol=20˜10) to give 2-mercapto-6-methyl-4,5,6,7-tetrahydropyrido[4,3-d][1,3]thiazole (525 mg, yield; 44%) as pale yellow amorphous.

1. additionafter the addition
2. concentrationThe reaction solution is concentrated under reduced pressure
3. additionto the resulting residue is added methylene chloride
4. concentrationThe mixture is concentrated under reduced pressure again
5. customthe resulting residue is crystallized from ether
6. customto give pale yellow crystals
7. additionfurther added
8. stirringThe mixture is stirred for one hour
9. stirringthe mixture is further stirred for additional one hour
10. stirringthe mixture is stirred for 30 minutes
11. washwashed with a saturated aqueous sodium hydrogen carbonate solution
12. dry with materialdried over sodium sulfate
13. concentrationconcentrated under reduced pressure
14. customThe residue is purified by silica gel column chromatography (methylene chloride/methanol=20˜10)

ORD record

ord-c5be3a56fcee414689055287a4ab3499

Source dataset

uspto-grants-2003_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06599895B1