Hydrochloric Acid → (2Z)-3-(phenylsulfanyl)prop-2-enoic acid

Temperature

0 °C

Methyl propiolate (3.37 ml, 40.0 mmol) was suspended in aqueous 2.5N NaOH (32.0 ml, 80 mmol), and the resulting mixture was cooled to 0° C. Thiophenol (4.12 ml, 40.0 mmol) was added drop wise under vigorous stirring, and the reaction was left at room temperature for 1 hour. The mixture was diluted with water (30 ml), and the pH was adjusted to 1 with aqueous 10% HCl. The aqueous solution was extracted with AcOEt (2×60 ml) and the combined organic layers were dried over Na2SO4 and evaporated to dryness (presence of two diastereoisomers, Z/E ratio about 90/10). The solid residue was suspended in CH3CN (20 ml) and heated to 40° C. to obtain complete dissolution. The solution was cooled to 0° C. and crystallization of the (Z) isomer was observed. The solid was collected by filtration and dried under vacuum affording (Z)-3-(phenylthio)acrylic acid (299a) (2.67 g, 14.81 mmol, 37% yield, MS/ESI+ 181.3 [MH]+).

1. extractionThe aqueous solution was extracted with AcOEt (2×60 ml)
2. dry with materialthe combined organic layers were dried over Na2SO4
3. customevaporated to dryness (presence of two diastereoisomers, Z/E ratio about 90/10)
4. temperatureheated to 40° C.
5. customto obtain complete
6. dissolutiondissolution
7. temperatureThe solution was cooled to 0° C.
8. customcrystallization of the (Z) isomer
9. filtrationThe solid was collected by filtration
10. customdried under vacuum

ORD record

ord-fd8c9fce57c4413cb6cd5bb95223dabe

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09265768B2