The present invention provides compounds of formula I: or a pharmaceutically acceptable salt thereof. Compounds of formula I are inhibitors of Janus kinases and as such are useful for the treatment of various diseases and conditions mediated by said enzymes, such as rheumatoid arthritis, asthma, COPD, ALS, and the like.
We report a mild and environmentally benign method for the synthesis of tertiary amines using alcohols as the alkylating reagents. Not only secondary amines such as piperazines but also amino acids and amino alcohols can be N-alkylated selectively. For N,O-benzyl protected amino alcohols, both N,O-de-benzylation and N-methylation were achieved in one-pot.