Synthesis and Cycloaddition Reaction of N-Phenyl-C-styrylmethanohydrazonyl Bromide

N-Phenyl-C_-sryrylnitrilimine 4 reacts with arylidenesulphanylaceto-nitriles 5a-c or arylidenemalononitriles 6a-c t o give exclusively 5-cyanopyrazoles 9a-c.On the other hand cyclaaddirion of ethyl arylidenecyanoacerate l l a , c , o -lH), 7.7 (d, J = 15Hz, l H ) , 7.0-8.0 (m , IOH) ppm; u (KBr) 1600 (C = N) c m .Anal.Calcd for C15H13BrN2: C, 59.8; H, 4.3; N, 9.3.Found: C, 59.7; H, 4.1; N, 9.1.Reaction of N-phenyl-C-styrylmethanohydruonyl bromide 3 with dipolarophiles 5, 6, 11-13 and 18.General method -T o a suspension of N-phenyl-C-scyrylmethanohydcazonyl bromide (1.5 g, 5 mmol) and t h e appropriate dipolarophile ( 5 mmol) in benzene (40 ml) was added triethylamine (0.7 ml, 5 mmol) ar room remperarure.T h e mixture was refluxed f o r 1 2 h and filrered ro get red of trierhylamine hydrobromide.T h e solvent was evaporated and t h e residue l e f t was triturated with a small amount of methanol where upon it solidified.The crude solid was collecred and recrystallization from acetic acid gave t h e corresponding cycloadducts 9a-c, 14a,c, 1%-d and 16a.Compound 9 a had mp 140°c, 1.14 g (70 %); 6 (CDC13) 6.8 ( d , J = lSHz, l H ) , 7.6 (d, J = 15Hc, lH), 7.2-7.8( m , 15H) ppm;( K B ~) 2250 ( C Z N ) cm-l.Anal.Calcd f a r CZ4H17N3: C, 82.9; H, 4.9; N, 12.1.Found: C, 83.0; H, 5.1; N, 11.9.Compound 9 b had m p 146%, 1.17 g (65 %); 6 (CDC13) 2.3 (s, 3H), 6.8 ( d , J = 1 5 H q l H ) , 7.5 ( d , 1 J = 15Hz, l H ) , 7.2-7.8( m , 14H) ppm; u (KBr) 2250 ( C = N ) cm-.Anal.Calcd for CZSHl9N3: C, 83.1; H, 5.3; N, 11.6.Found: C, 83.1; H, 5.1; N, 11.2.Compound 9c had mp 199'c, 1.43 g (75 %); 6 ( c D c I ~) 6.9 ( d , J = 15Hz, l H ) , 7.7 (d, J = 15Hr, 1 l H ) , 7.2-7.9( m , 14H) ppm; u ( K B ~) 2250 (C s N) cm-.Anal.Calcd for CZ4Hl6CINi C, 75.5;H, 4.2; N, 11.1.Found: C, 75.3;H, 4.1; N, 11.3.Compound 14a had mp 126'c, 1.26 g (60 %); 6 ( C D C I ~) 1.3 ( t , J = ?Hz, 3H), 4.4 (q, 1 = 7Hz, 2H), 5.1 (s, I H ) , 6.7 ( d , J = 15Hz, l H ) , 7.6 ( d , J = lSHz, l H ) , 7.0-7.8( m , 15H) ppm; u (KBr) 1 1740 (C = O ) cm-.Anal.Calcd far CZ7Hz3N3O2: C, 76.9; H, 5.5; N, 9.9.