An efficient method for synthesizing dimethylsulfonio- 34 S-propionate hydrochloride from 34 S 8 .

Dimethylsulfoniopropionate (DMSP, (2-carboxyethyl)dimethylsulfonium) is a highly abundant compound in marine environments. As a precursor to the climatically active gas, dimethylsulfide (DMS), DMSP connects the marine and terrestrial sulfur cycles. However, the fate of DMSP in microbial biomass is not well understood as only a few studies have performed isotopic labeling experiments. A previously published method synthesized 34 S-labeled DMSP from 34 S8 , but the efficiency was only 26 % and required five separate reactions, expensive reagents, and purification of the products of each reaction. In this study, a method of synthesizing 34 S-labeled DMSP from 34 S8 is described. Improvements include elemental steps, inexpensive reagents, purification of only one intermediate, and less time to complete. The efficiency of this method is 65 % and results in pure DMSP with >98 % isotope enrichment as determined by 1 H-NMR and GC-MS.