ACS case studies
ACS · Put your knowledge to work in context.
The ACS Certified Chemist credential is a professional certification offered by the American Chemical Society for chemists who want independent, third-party validation of their breadth of knowledge across the chemical sciences. It appeals to recent graduates entering industry, experienced bench chemists seeking formal recognition, and professionals moving into roles where demonstrated competence across subdisciplines matters, such as quality, regulatory, or research leadership. The ACS case studies are 5 cases and about 4,491 words.
1Transfer of a Weakly Basic API Assay: pH, Column Chemistry, and a Failed Resolution
A contract laboratory is transferring your validated reversed-phase assay for a weakly basic API (pKa 8.4) onto its own equipment. The originating method uses a 150 x 4.6 mm C18 column, 10 mM phosphate buffer pH 7.0 / acetonitrile (60:40), 1.0 mL/min, 30 C, and resolves the API from a known degradant at RRT 0.92 with resolution 2.4, tailing factor 1.1 and 9,000 plates.
932 words, about 5 min2Enantiomeric Erosion During an Amide Coupling to a Weakly Nucleophilic Aniline
A process team is coupling N-acetyl-(S)-2-amino-4-phenylbutanoic acid with 4-nitroaniline to make a key intermediate. The current route uses HATU (1.1 equiv) and DIPEA (2.0 equiv) in DMF at 20 C.
849 words, about 4 min3Accumulation-Limited Exotherm: MTSR, TMRad and a Scale-Up Sign-Off
A 1.20 mol batch of an aromatic substitution runs in a 6 L jacketed reactor at 40 C. Reaction calorimetry gives a reaction enthalpy of -240 kJ per mol of limiting substrate; the charged mass is 3.6 kg with a mean heat capacity of 2.5 J g-1 K-1.
902 words, about 5 min4A Catechol-Containing Screening Hit That Inhibits Everything
A high-throughput screen of 180,000 compounds against a serine protease returns compound 14 with IC50 = 1.2 uM in a fluorogenic peptide assay (10 nM enzyme, 20 uM substrate, Km = 25 uM). The Hill slope is 2.8.
864 words, about 4 min5A Polyester That Misses Its Molecular Weight Target and Shows a High-MW Shoulder
A melt transesterification of dimethyl terephthalate and 1,4-butanediol is run with 250 ppm titanium tetrabutoxide under a nitrogen sparge, programmed to 245 C over 4 h with vacuum applied in the final hour. The charge is calculated for exactly 1.00:1.00 mol ratio and a target Mn of 20,000 g/mol (repeat unit 220 g/mol).
944 words, about 5 min