Discovery of novel SCD1 inhibitors: 5-alkyl-4,5-dihydro-3H-spiro[1,5-benzoxazepine-2,4'-piperidine] analogs.

Expansion of the 6-membered ring and subsequent fine-tuning of the newly obtained 7-membered spiropiperidine structure resulted in the discovery of a series of novel and potent SCD1 inhibitors. Preliminary SAR was explored by modifying an alkyl chain on the azepine nitrogen and resulted in the identification of a highly potent SCD1 inhibitor: 6-[5-(cyclopropylmethyl)-4,5-dihydro-1'H,3H-spiro[1,5-benzoxazepine-2,4'-piperidin]-1'-yl]-N-(2-hydroxy-2-pyridin-3-ylethyl)pyridazine-3-carboxamide (9). Compound 9 exhibited an IC(50) value of 0.01 μM against human SCD1.