We describe a scheme to determine the major sulfur species found in marine porewaters. With polarographic techniques, it is possible to measure thiosulfate, sulfite, bisulfide, and polysulfide ions at a mercury electrode. Polysulfide ions, SX2--, can be considered to be composed of one sulfur in the 2-oxidation state, S(2-), and the remaining (x -1) sulfurs in the zero-valent oxidation state, S(0). The number of sulfur atoms in each is measurable. Tetrathionate and other polythionates can be measured as well but have not been detected in porewaters studied to date. Salt marsh and subtidal porewater profiles contain significant concentrations of thiosulfate, bisulfide, and polysulfide. The ratio of S(2-) to S(0) is higher in subtidal porewaters than in salt marsh porewaters and indicates the importance of zero-valent sulfur to the biogeochemical processes prevalent in the salt marsh ecosystem. The S(0) concentrations in porewaters from salt marsh sediments are greater than those predicted from equilibrium calculations.

The development of a large scale synthesis of the glucocorticoid agonist BI 653048 BS H3PO4 (1·H3PO4) is presented. A key trifluoromethyl ketone intermediate 22 containing an N-(4-methoxyphenyl)ethyl amide was prepared by an enolization/bromine-magnesium exchange/electrophile trapping reaction. A nonselective propargylation of trifluoromethyl ketone 22 gave the desired diastereomer in 32% yield and with dr = 98:2 from a 1:1 diastereomeric mixture after crystallization. Subsequently, an asymmetric propargylation was developed which provided the desired diastereomer in 4:1 diastereoselectivity and 75% yield with dr = 99:1 after crystallization. The azaindole moiety was efficiently installed by a one-pot cross coupling/indolization reaction. An efficient deprotection of the 4-methoxyphenethyl group was developed using H3PO4/anisole to produce the anisole solvate of the API in high yield and purity. The final form, a phosphoric acid cocrystal, was produced in high yield and purity and with consistent control of particle size.

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