Condensation Reactions of a Nitrodienamine with Grignard Reagents Prepared from Phenyl Bromide, Bromotoluene, Indoles, and Carbazole

Condensation reactions of a nitrodienamine (1 )with Grignard reagents prepared from phenyl bromide, 4bromotoluene, indole (6a), 3-methylindole (6b), 2,3dimethylindole (6c), 3-cyanomethylindole (6d), and carbazole (6e) were investigated.We are interested in the reactivities of nitrodienamines and aminodienyl esters having enaminic and diene moieties and an electronic "push-pull" character that can lead to interesting cycloaddition rea~tions.'.~In a previous study,6 we reported a synthesis of nitrodienamine, 1 -( N , Ndimethylamino)--4-nitro-1,3-butadiene (I), some cycloadditions of 1 witha, P-unsaturated carbonyl compounds and quinones, and condensations with nucleophiles.In this paper we describe the condensation reactions of 1 with Grignard reagentsto afford the corresponding products ( 3 ) , (5) and/or ( 9 1 , (10).The Grignard reagents were prepared from phenyl bromide, 4bromotoluene, indole (6a), 3-methylindole (6b), 2,3-dimethylindole (6c), H z , o l e f i n i c H ) , 7 .1 6 ( l H , d, J = 1 5 .3 Hz, o l e f i n i c H ) , 6.87 ( l H , dd, J = 1 5 .3 , 1 1 .6 Hz, o l e f i n i c H ) .High MS m/z: C a l c d f o r C,,H,NO, M : 175.0633.Found: 1 7 5 .0 6 3 5 .A n a l .C a l c d f o r C,,H,NO,: C, 68.56; H, 5 . 1 8 ; N, 8 .0 0 .Found: C, 68.48; H, 5.24; N, 8 . 1 4 . The Reaction of t h e Nitrodienamine (1) with p-TolylmagnesiumBromide (4) 1 M p-TolylMgBr i n e t h e r s o l u t i o n : 1 mL, 1 mmol.R e a c t i o n t i m e : 2 h .S o l v e n t f o r -c h r o m a t o g r a p h y : 10% e t h y l a c e t a t e i n h e x a n e .P r o d u c t : 6 .3 mg ( 3 3 .3 % ) of l-( p -t o l y l ) -4 -n i t r o -l , 3 -b u t a d i e n e ( 5 ) a s o r a n g e p r i s m s ( e t h e r -h e x a n e ) , t , J = 1 2 .6 Hz, o l e f i n i c H ) , 7 .4 1 (2H, d, J = 8 . 2 Hz, a r o m a t i c H I , 7 .2 3 ( l H , t , J = 1 2 .6 Hz, o l e f i n i c H) , 7 .2 1 (2H, d , J = 7 .9 Hz, a r o m a t i c H ) , 7.12 ( l H , d , J = 1 5 .3 H z , o l e f i n i c H ) , 6 .8 2 ( l H , dd, J = 1 5 .6 and 1 1 .6 Hz, o l e f i n i c H ) , 2 .3 8 (3H, s, M e ) .High MS m/z: C a l c d f o r C,,H,,NO, M : 189.0787.