Synthesis of triazolopyrimidine compounds

摘要

The present invention relates to the field of organic synthesis and describes the synthesis of specific triazolopyrimidine compounds and intermediates thereof as well as related derivatives, suitable for the preparation of Ticagrelor (TCG).

主权项

1. A process for the preparation of a compound of formula Va or Vb wherein Pg is an amino protecting group, and Z is hydrogen, hydroxyethyl or a group convertible to hydroxyethyl, the process comprising the steps of: (i) reacting a compound of formula II′ wherein Pg is defined as above, with a compound of the formula VI or VII wherein Z is defined as above, to obtain a compound of formula IIIa′ or IIIb′, respectively wherein Pg and Z are as defined above, (ii) reducing the nitro group in the compound of formula IIIa′ or IIIb′ to an amino group to obtain a compound of formula IVa′ or IVb′, respectively, and (iii) nitrosation of the compound of formula IVa′ or IVb′ to obtain the compound of formula Va or Vb, respectively.