1-Bromo-3-chloropropane → HCID 20505181, compound

Temperature

70 °C

A 10 N aqueous solution of sodium hydroxide (39 cc) is added dropwise, in the course of 15 minutes and at a temperature of about 10° C., to a solution of 2-(pyrazinylmethyl)-isothiourea monohydrochloride (77.6 g) in distilled water (250 cc). After heating for 30 minutes at 70° C. and then cooling to 15° C., a 10 N aqueous solution of sodium hydroxide (47 cc) and then 1-bromo-3-chloropropane (66.5 g) are added and stirring is continued for 15 hours at a temperature of about 20° C. The reaction mixture is then extracted three times with methylene chloride (280 cc in total). The organic extracts are combined, washed twice with distilled water (200 cc in total), dried over anhydous sodium sulphate and filtered. The solution obtained is poured onto neutral silica gel (80 g) contained in a column of diameter 2.7 cm; the column is then eluted with methylene chloride (900 cc). The first fraction (300 cc) is discarded; the second fraction (600 cc) is collected and concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 35° C. Pyrazinylmethyl 3-chloropropyl sulphide (59 g) is thus obtained in the form of a yellow-orange oil.

1. temperaturecooling to 15° C.
2. extractionThe reaction mixture is then extracted three times with methylene chloride (280 cc in total)
3. washwashed twice with distilled water (200 cc in total)
4. dry with materialdried over anhydous sodium sulphate
5. filtrationfiltered
6. customThe solution obtained
7. additionis poured onto neutral silica gel (80 g)
8. washthe column is then eluted with methylene chloride (900 cc)
9. customthe second fraction (600 cc) is collected
10. concentrationconcentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 35° C

ORD record

ord-1d8aacc727ca424dbf6fe9237af0e4cf

Source dataset

uspto-grants-1983_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04379154