(2S)-2-amino-4-ethyl-2-methylhexanoic acid 、 苯磺酸 以
乙腈 为溶剂,
反应 16.0h,
以to give the title compound as fine white needles, (16.5 g, 86%)的产率得到(2S)-2-amino-4-ethyl-2-methylhexanoic acid benzene sulphonate
The present invention relates to a method of treating pain using a compound of formula
wherein R
1
, R
2
, R
3
and R
4
are as defined herein. The invention also relates to certain novel derivatives of formula (I).