Pseudoephedrine → (4S,5S)-2-Allyl-2-chloro-3,4-dimethyl-5-phenyl-1-oxa-3-aza-2-silacyclopentane

To a cooled (0° C.) solution of allyltrichlorosilane (101 mL, 0.696 mol) in methylene chloride (1.8 L) under argon was added triethylamine (170 mL, 1.21 mol). (1S,2S)-pseudoephedrine (100 g, 0.605 mol) was then added portionwise over 30 min, to maintain internal temperature below 15° C. After the addition was complete the mixture was stirred for 12 hours at ambient temperature. The methylene chloride was removed by distillation and the residue was diluted with pentane (1.5 L). The mixture was vigorously stirred for 12 hours to ensure complete precipitation of the triethylamine salts. Filtration of the resulting suspension through a pad of celite and concentration of the filtrate by distillation afforded the crude product as a pale yellow oil. Purification by distillation under reduced pressure (bp˜120 C, 5 mm Hg) provided 149 g (92%) of (4S, 5S)-2-Allyl-2-chloro-3,4-dimethyl-5-phenyl-[1,3,2]oxazasilolidine as a ˜2:1 mixture of diastereomers.

1. temperatureto maintain internal temperature below 15° C
2. additionAfter the addition
3. customThe methylene chloride was removed by distillation
4. additionthe residue was diluted with pentane (1.5 L)
5. stirringThe mixture was vigorously stirred for 12 hours
6. customprecipitation of the triethylamine salts
7. filtrationFiltration of the resulting suspension through a pad of celite and concentration of the filtrate
8. distillationby distillation
9. customafforded the crude product as a pale yellow oil
10. customPurification
11. distillationby distillation under reduced pressure (bp˜120 C, 5 mm Hg)

ORDレコード

ord-1b8587800f224a88aab7b3665d6df2c3

出典データセット

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07534905B2