A Combination of Flow and Batch Mode Processes for the Efficient Preparation of mGlu2/3 Receptor Negative Allosteric Modulators (NAMs).

Benzodiazepinones are privileged scaffolds with activity against multiple therapeutically relevant biological targets. In support of our ongoing studies around allosteric modulators of metabotropic glutamate receptors (mGlus) we required the multigram synthesis of a ß-ketoester key intermediate. We report the continuous flow synthesis of tert-butyl 3-(2-cyanopyridin-4-yl)-3-oxopropanoate and its transformation to potent mGlu2/3 negative allosteric modulators (NAMs) in batch mode.

Design, synthesis and evaluation of benzoisothiazolones as selective inhibitors of PHOSPHO1.

We report the discovery and characterization of a series of benzoisothiazolone inhibitors of PHOSPHO1, a newly identified soluble phosphatase implicated in skeletal mineralization and soft tissue ossification abnormalities. High-throughput screening (HTS) of a small molecule library led to the identification of benzoisothiazolones as potent and selective inhibitors of PHOSPHO1. Critical structural requirements for activity were determined, and the compounds were subsequently derivatized and measured for in vitro activity and ADME parameters including metabolic stability and permeability. On the basis of its overall profile the benzoisothiazolone analogue 2q was selected as MLPCN probe ML086.

Design and synthesis of systemically active metabotropic glutamate subtype-2 and -3 (mGlu2/3) receptor positive allosteric modulators (PAMs): pharmacological characterization and assessment in a rat model of cocaine dependence.

As part of our ongoing small-molecule metabotropic glutamate (mGlu) receptor positive allosteric modulator (PAM) research, we performed structure-activity relationship (SAR) studies around a series of group II mGlu PAMs. Initial analogues exhibited weak activity as mGlu2 receptor PAMs and no activity at mGlu3. Compound optimization led to the identification of potent mGlu2/3 selective PAMs with no in vitro activity at mGlu1,4-8 or 45 other CNS receptors. In vitro pharmacological characterization of representative compound 44 indicated agonist-PAM activity toward mGlu2 and PAM activity at mGlu3. The most potent mGlu2/3 PAMs were characterized in assays predictive of ADME/T and pharmacokinetic (PK) properties, allowing the discovery of systemically active mGlu2/3 PAMs. On the basis of its overall profile, compound 74 was selected for behavioral studies and was shown to dose-dependently decrease cocaine self-administration in rats after intraperitoneal administration. These mGlu2/3 receptor PAMs have significant potential as small molecule tools for investigating group II mGlu pharmacology.

Orally active metabotropic glutamate subtype 2 receptor positive allosteric modulators: structure-activity relationships and assessment in a rat model of nicotine dependence.

Compounds that modulate metabotropic glutamate subtype 2 (mGlu(2)) receptors have the potential to treat several disorders of the central nervous system (CNS) including drug dependence. Herein we describe the synthesis and structure-activity relationship (SAR) studies around a series of mGlu(2) receptor positive allosteric modulators (PAMs). The effects of N-substitution (R(1)) and substitutions on the aryl ring (R(2)) were identified as key areas for SAR exploration (Figure 3). Investigation of the effects of varying substituents in both the isoindolinone (2) and benzisothiazolone (3) series led to compounds with improved in vitro potency and/or efficacy. In addition, several analogues exhibited promising pharmacokinetic (PK) properties. Furthermore, compound 2 was shown to dose-dependently decrease nicotine self-administration in rats following oral administration. Our data, showing for the first time efficacy of an mGlu(2) receptor PAM in this in vivo model, suggest potential utility for the treatment of nicotine dependence in humans.

Potent, selective, and orally available benzoisothiazolone phosphomannose isomerase inhibitors as probes for congenital disorder of glycosylation Ia.

We report the discovery and validation of a series of benzoisothiazolones as potent inhibitors of phosphomannose isomerase (PMI), an enzyme that converts mannose-6-phosphate (Man-6-P) into fructose-6-phosphate (Fru-6-P) and, more importantly, competes with phosphomannomutase 2 (PMM2) for Man-6-P, diverting this substrate from critical protein glycosylation events. In congenital disorder of glycosylation type Ia, PMM2 activity is compromised; thus, PMI inhibition is a potential strategy for the development of therapeutics. High-throughput screening (HTS) and subsequent chemical optimization led to the identification of a novel class of benzoisothiazolones as potent PMI inhibitors having little or no PMM2 inhibition. Two complementary synthetic routes were developed, enabling the critical structural requirements for activity to be determined, and the compounds were subsequently profiled in biochemical and cellular assays to assess efficacy. The most promising compounds were also profiled for bioavailability parameters, including metabolic stability, plasma stability, and permeability. The pharmacokinetic profile of a representative of this series (compound 19; ML089) was also assessed, demonstrating the potential of this series for in vivo efficacy when dosed orally in disease models.

Design and synthesis of an orally active metabotropic glutamate receptor subtype-2 (mGluR2) positive allosteric modulator (PAM) that decreases cocaine self-administration in rats.

The modification of 3'-((2-cyclopentyl-6,7-dimethyl-1-oxo-2,3-dihydro-1H-inden-5-yloxy)methyl)biphenyl-4-carboxylic acid (BINA, 1) by incorporating heteroatoms into the structure and replacing the cyclopentyl moiety led to the development of new mGluR2 positive allosteric modulators (PAMs) with optimized potency and superior druglike properties. These analogues are more potent than 1 in vitro and are highly selective for mGluR2 vs other mGluR subtypes. They have significantly improved pharmacokinetic (PK) properties, with excellent oral bioavailability and brain penetration. The benzisothiazol-3-one derivative 14 decreased cocaine self-administration in rats, providing proof-of-concept for the use of mGluR2 PAMs for the treatment of cocaine dependence.