method for measuring the concentration of nitrogen in argon mediantespettroscopia ionic mobility.

摘要

Described herein is a process for the preparation of 6 alpha -fluorosteroids of formula (I), in which R is chosen from H, OH and an alkyl group with from 1 to 4 carbon atoms and R' is a carboxyalkyl group with from 1 to 4 carbon atoms in the alkyl chain, comprising the selective fluorination at the 6 alpha -position CHEM by treatment of the compound of formula (III), wherein R and R' are as defined above, with an electrophilic fluorinating agent.