Cysteamine Hydrochloride → 2-(4-Bromophenyl)-1,3-thiazolidine

To a solution of 4-bromobenzaldehyde (2.5 g, 13.5 mmol) in EtOH (15 ml) was added a solution of cysteamine HCl (0.5 g, 4.4 mmol) in water (5 ml) dropwise with stirring. The solution was then stirred at RT for 18 h before the bulk of the EtOH was removed by rotary evaporator. The residue was diluted with water (15 ml) and extracted with ether (3×20 ml) to remove excess aldehyde. The acidic aqueous layer was then basified with the slow addition of solid sodium carbonate (0.3 g) to give a heavy white precipitate, which was filtered and washed carefully with water (3×10 ml). The solid was dried in a vacuum desiccator to give 2-(4-bromophenyl)-1,3-thiazolane (4) as a white crystalline solid (0.73 g, 68%), mp 107° (lit. mp, 105-107°). 1H nmr (d6-dmso, 300 MHz) 2.4, br s, NH; 3.05-3.2, m, H4,4,5; 3.5-3.6, m, H5; 5.55, s, H2; 7.38, d (8.4 Hz), ArH; 7.47, d (8.4), ArH. ESI (+ve) MS m/z 287/285 (M+MeCN+H, 30%), 246/244 (M+H, 100).

1. customwas removed by rotary evaporator
2. additionThe residue was diluted with water (15 ml)
3. extractionextracted with ether (3×20 ml)
4. customto remove excess aldehyde
5. additionThe acidic aqueous layer was then basified with the slow addition of solid sodium carbonate (0.3 g)
6. customto give a heavy white precipitate, which
7. filtrationwas filtered
8. washwashed carefully with water (3×10 ml)
9. customThe solid was dried in a vacuum desiccator

ORD record

ord-2895b1048a67494cb56ed1186e09ae7f

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07863313B2