Yields obtained in the synthesis of 1,5-benzodiazepines and 3.4-dihydroquinoxalines using deuterated acetone^a.

Starting material	X	Product	R1	R2	R3	R4	Acetone-d6 yield% (time)
6a	O	10g	H	H	Tetramethylbutyl	CD3	57 (24 h)
6a	O	10h	H	H	Cyclohexyl	CD3	61 (24 h)
6a	O	11i	H	H	t-Bu	CD3	70 (24 h)
6c	O	11j	Cl	Cl	t-Bu	CD3	72 (24 h)
6c	O	11k	Cl	Cl	Tetramethylbutyl	CD3	80 (24 h)

^aReaction conditions: isocyanide 2 (1 eq.), deuterated acetone 3c (2 eq.) and benzimidazole derivative 6 (1 eq.) were stirred at room temperature for 24 h.