Selective deprotection of N-heteroaromatic carbamates under basic conditions

30 June 2006

A recent publication from workers at Novartis* describes a mild base catalysed deprotection of N-heteroaromatic carbamates. This allows removal of Boc and Cbz protecting under basic conditions and the reaction is selective for the N-heteroaryl carbamate group as shown in the example below.

In a typical reaction the substrate is stirred at room temperature with a base such as sodium methoxide or Verkade’s base (phosphazine base) for 2-40 hours) and yields over 95% are reported in all cases.

*W-C. Shieh et al., Tetrahedron Letters 2006, 47, 5645-5648.