Sintesis Senyawa Turunan 2-Metoksi-3H-Azepina Melalui Reaksi Termal antara Alkylnitrobenzena dan Tributilphosphina

Abstract

Although photolysis of phenyazide has been widely reported to give 3 H -azepine, the thermal deoxygenation reaction of alkylnitrobenzene derived similar products hitherto unexplored. Novel synthesis of 2-methoxy-3 H -azepine derivatives was carried out using alkylnitrobenzene with tributylphosphine (Bu 3 P) reacted at 150°C for 24 hours in the presence of methanol. Reaction of m -nitrobenzene with the above methods gave two isomers of 3 H -azepine, namely, 2-methoxy-6-methyl-3 H -azepine and 2-methoxy-4-methyl-3 H -azepine in 61%. Reaction of 2,3-dimethylnitrobenzene with Bu 3 P afforded the three isomers, that is, 2-methoxy-6,7-dimethyl-3 H -azepine; 2-methoxy-3,4-dimethyl-3 H -azepine and 7-methoxy-5,6-dimethyl-4 H -azepine. Reaction of 3,5-dimethylnitrobenzene gave the sole product of 2-methoxy-4,6-dimethyl-3 H -azepine in 42%. In contrast, reaction of 2,6-dimethylnitrobenzene didn’t give any product because the steric effect of methyl groups attached on C2 and C6. Structure elucidation of all novel products have confirmed by HETCOR.