Parallel solution phase synthesis of N-substituted 2-pyrazoline libraries

The value of α,β-unsaturated ketones (chalcones) as templates for the combinatorial assembly of N-substituted 2-pyrazolines has been explored. Based on a set of 80 chalcones, an array of 1500 N-carbamoyl, carbonyl and sulfonyl pyrazolines were produced demonstrating that a broad range of diversity can be fabricated around the pyrazoline motif. The efficient utilization of polymer-supported reagents and scavengers aided in providing typical purities of 75–98%.