The Synthetic and Theoretical Studies on Nitration Selectivity of Benzo-1,2,3,4-Tetrazine-1,3-Dioxide (BTDO)

The Synthetic and Theoretical Studies on Nitration Selectivity of Benzo-1,2,3,4-tetrazine-1,3-dioxide (BTDO)

Tianyi Wang, Wenjie Wei, Xuedong Gong*, Mingzhu Xia*

(School of Chemical Engineering, NUST, Nanjing 210094, China)

Abstract£º 5-Nitrobenzene-1,2,3,4-tetrazine-1,3-dioxide (5-NBTDO) and 7-nitrobenzene-1,2,3,4-tetrazine-1,3-dioxide (7-NBTDO)  were synthesized using benzo-1,2,3,4-tetrazine-1,3-dioxide (BTDO) as raw material. Then the 5,7-dinitrobenzene-1,2,3,4-tetrazi ne-1,3-dioxide (DNBTDO) was synthesized by 5-NBTDO and 7-NBTDO as raw material. The structures of synthesized compounds were characterized by ¹H NMR, ¹³C NMR, IR and MS. The effects of nitration system, material ratio n(BTDO):n(NO₃ ^-)  and reaction temperature on the yields of different nitrating products were explored. Possible nitration products were predicted through theoretical means. The yields of the products were detected by HPLC. Results show that the optimum process conditions of synthesizing three substances were determined as: for oleum-KNO₃ nitration system. n(BTDO)£ºn(KNO₃) =1£º2 , reaction temperature 40 °æ , with yield of 5-NBTDO 34.9%; for nitric acid-sulfuric acid mixed system, n(BTDO)£ºn(HNO₃) =1£º3, reaction temperature 20°æ,with yield of 7-NBTDO 77.1%; for oleum-nitric acid system, n(NBTDO)£ºn(HNO₃) =1£º8, and reaction temperature 95°æ,with yield of DNBTDO 90%.The yield of three kinds of nitration products, synthesized via one-step method using BTDO, is consistent with the theory prediction. The order of yield is 7-NBTDO>5-NBTDO>DNBTDO.

Key words: benzo-1, 2, 3, 4-tetrazine-1, 3-dioxide (BTDO); orthogonal experiment; nitration technology

Scheme 1 The nitration route of BTDO

Fig. 1 Dual descriptor distribution isosurface graph of BTDO