Process Chemistry News
This paper describes a Boc removal method using TMS iodide (TMSI) which is ideal for producing zwitterionic products. The substrate is treated with TMSI in acetonitrile at 0°C. At the end of the reaction a limited amount of water is added and the product crystallises directly in high purity.
OPRD has just published as an ASAP article a long and very comprehensive multi-author review (with hundreds of up-to-date references) showing the state of the art in PAT. (Levente S; doi 10.1021/op500261y). It is particularly strong in crystallisation technologies and has some good industrial case studies. The review forms part of a special feature section devoted to PAT which will appear in the Jan 2015 edition of OPRD.
Workers at Merck wanted to hydrolyse nitrile (20) to acid (2), so they chose to heat the nitrile in 5N HCl at 40°C. They were somewhat surprised to obtain the desired acoid (2) contaminated with isomer (21) formed in up to 15% yield or a ratio of 89:11.
J.Y.L. Chung,* Y.-L. Zhong,* K.M. Maloney,* R.A. Reamer, J.C. Moore, H. Strotman, A. Kalinin, R. Feng, N.A. Strotman, B. Xiang, and N. Yasuda, Org. Lett., 2014, 16, 5890-5893.