We report an automated flow chemistry platform that can efficiently perform a wide range of chemistries, including single/multi-phase and single/multi-step, with a reaction volume of just 14 μL. The breadth of compatible chemistries is successfully demonstrated and the desired products are characterized, isolated, and collected online by preparative HPLC/MS/ELSD.

The paper will describe the use of flow chemistry for scaling up exothermic or hazardous nitration reactions. Such reactions often cause time delays to the delivery of larger batches of intermediates or final compounds for medicinal chemistry projects, because considerable time is required for safety evaluation and, if necessary, modification of the procedure so that it can be scaled-up and run in a safe manner. A commercially available continuous flow reactor was used in the scale up of three challenging nitrations including a reaction involving a potentially explosive mixture of acetic acid and fuming nitric acid, with a productivity of 97 g/h.

An evaluation of a new bench-top microwave batch reactor that uses a single 1 L reaction vessel is presented. Several microwave-assisted organic reactions have been scaled-up, including Newman Kwart and DielsÀAlder reactions, Pd-catalyzed crosscouplings, heterocycle synthesis, aromatic substitution, and a Knoevenagel condensation. A range of different solvents (high and low microwave absorbing), varying reaction times (4 s up to 2 h), and temperatures (120À250°C) have been explored in these investigations. For all studied transformations, it was possible to perform a direct scale-up (up to 720 mL reaction volume) without changing the previously optimized reaction conditions achieved in a laboratory-scale single-mode microwave instrument (2À20 mL processing volume), obtaining similar isolated product yields. A scalability up to 360-fold, when moving from 3 mmol up to 1.08 mol, was demonstrated, and isolated product yields up to 300 g (2.5 mol scale) in a single run could be accomplished, providing the potential for a kilogram output per day for specific transformations by performing multiple sequential runs.

A novel 2,6-naphthyridine was identified by high throughput screen (HTS) as a dual protein kinase C/D (PKC/PKD) inhibitor. PKD inhibition in the heart was proposed as a potential antihypertrophic mechanism with application as a heart failure therapy. As PKC was previously identified as the immediate upstream activator of PKD, PKD vs PKC selectivity was essential to understand the effect of PKD inhibition in models of cardiac hypertrophy and heart failure. The present study describes the modification of the HTS hit to a series of prototype pan-PKD inhibitors with routine 1000-fold PKD vs PKC selectivity. Example compounds inhibited PKD activity in vitro, in cells, and in vivo following oral administration. Their effects on heart morphology and function are discussed herein.

A green approach towards the on-demand in-line generation of MNU and diazomethane in a continuous flow.

Parathyroid hormone (PTH) is an effective bone anabolic agent. However, only when administered by daily sc injections exposure of short duration is achieved, a prerequisite for an anabolic response. Instead of applying exogenous PTH, mobilization of endogenous stores of the hormone can be envisaged. The secretion of PTH stored in the parathyroid glands is mediated by a calcium sensing receptor (CaSR) a GPCR localized at the cell surface. Antagonists of CaSR (calcilytics) mimic a state of hypocalcaemia and stimulate PTH release to the bloodstream. Screening of the internal compound collection for inhibition of CaSR signaling function afforded 2a. In vitro potency could be improved >1000 fold by optimization of its chemical structure. The binding mode of our compounds was predicted based on molecular modeling and confirmed by testing with mutated receptors. While the compounds readily induced PTH release after iv application a special formulation was needed for oral activity. The required profile was achieved by using microemulsions. Excellent PK/PD correlation was found in rats and dogs. High levels of PTH were reached in plasma within minutes which reverted to baseline in about 1-2 h in both species.

A range of pharmaceutically relevant reactions were investigated for scale-up in a kilo-lab environment using a commercial batch microwave reactor. Typical scale-up issues are discussed, taking into account the specific limitations of microwave heating in large-scale experiments. Examples of scale-up from 15 mL to 1 L are presented and demonstrate that the synthesis of compounds on greater than 100 g scale is feasible in one batch. Aided by this new technology reaction times have been significantly reduced and the productivity of our scale-up laboratory has been enhanced. Production rates of several hundred grams per day were achieved using microwave technology. The article concludes with a brief discussion of advantages and disadvantages of this type of batch microwave reactor.

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