1 6 alkyl c 2 6 alkenyl c 2 6 alkynyl c 3 6 cycloalkyl aryl heterocyclyl and heteroaryl while the substituent s may be identical or different and are selected from among halogen u2014 no 2 u2014 or 4 u2014 c u2550 o r 4 u2014 c u2550 o or 4 u2014 c u2550 o nr 4 r 5 u2014 nr 4 r 5 u2014 nr 4 c u2550 o r 5 u2014 nr 4 c u2550 o or 5 u2014 nr 4 c u2550 o nr 5 r 6 u2014 nr 4 so 2 r 5 u2014 n u2550 cr 4 r 5 u2014 sr 4 u2014 sor 4 u2014 so 2 r 4 u2014 so 2 nr 4 r 5 u2014 nr 4 so 2 nr 5 r 6 u2014 oso 2 nr 5 r 6 and pseudohalogen r a r b r c r d r e r f r g and r h in each case independently of one another denote a group selected from among hydrogen halogen u2550 o u2014 no 2 u2014 or 4 u2014 c u2550 o r 4 u2014 c u2550 o or 4 u2014 c u2550 o nr 4 r 5 u2014 nr 4 r 5 u2014 nr 4 c u2550 o r 5 u2014 nr 4 c u2550 o or 5 u2014 nr 4 c u2550 o nr 5 r 6 u2014 nr 4 so 2 r 5 u2014 n u2550 cr 4 r 5 u2014 c u2550 nr i u2014 sr.