Iodine → Methyl 3-[(2,2-dimethylbutanoyl)thio]propanoate

Temperatur

25 °C

A solution of N,N-diisopropylethylamine (19.9 mL, 120 mmol) and methyl 3-mercaptopropanoate (7.21 60 mmol) in isopropyl acetate (i-PrOAc, 100 mL) was cooled to an internal temperature of 2° C. (brine ice bath). To this vigorously stirred solution was added 2,2-dimethylbutanoyl chloride (8.1 g, 60 mmol) dropwise over 10 min. The resulting suspension was then stirred at 25° C. for 2 h. The reaction was monitored by checking the disappearance of methyl 3-mercaptopropanoate using thin-layer chromatography (TLC) on silica plates. Spots were stained with iodine (eluent: 5% EtOAc/heptane; Rf of methyl 3-mercaptopropanoate: 0.20). The reaction was then quenched by addition of saturated ammonium chloride (100 mL) followed by i-PrOAc (100 mL) and the resultant mixture was stirred until all solid dissolved. The phases were separated and the organic phase was washed successively with 1% aqueous hydrochloric acid (100 mL) and then water (2×50 mL). The organic phase was then dried over sodium sulfate, filtered, and concentrated under reduced pressure (45° C. bath, 50 mm Hg) to obtain a crude mixture as a pale yellow liquid. The crude mixture was subjected to column chromatography over silica gel using a heptane to 2% EtOAc:heptane gradient. Fractions comprising the pure product were combined and concentrated to afford 10.5 g (80%) of methyl 3-(2,2-dimethylbutanoylthio)propionate.

1. customThe reaction was then quenched by addition of saturated ammonium chloride (100 mL)
2. stirringthe resultant mixture was stirred until all solid
3. dissolutiondissolved
4. customThe phases were separated
5. washthe organic phase was washed successively with 1% aqueous hydrochloric acid (100 mL)
6. dry with materialThe organic phase was then dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure (45° C. bath, 50 mm Hg)
9. customto obtain a crude mixture as a pale yellow liquid
10. concentrationconcentrated

ORD-Eintrag

ord-70a409921fed4571b4e1889fed2c462f

Quelldatensatz

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09399785B2