пришлите, пожалуйста, статью:
Synthesis of substituted 1,3-oxazines using sulfamic acid as an efficient and eco-friendly catalyst
M. Damodiran, Paramasivan T. Perumal
- DOI:
http://dx.doi.org/10.1002/jhet.489
Volume 47, Issue 6, pages 1386–1391, November 2010
спасибо.