Abstract :
We have recently reported the molecular and supramolecular structures of the recreational drug N-(4-methoxyphenyl)piperazine (4-MeOPP) (Kiran Kumar et al., 2020[Kiran Kumar, H., Yathirajan, H. S., Harish Chinthal, C., Foro, S. & Glidewell, C. (2020). Acta Cryst. E76, 488-495.]) and those of a range of salts formed by 4-MeOPP with organic acids (Kiran Kumar, Yathirajan, Foro et al., 2019[Kiran Kumar, H., Yathirajan, H. S., Foro, S. & Glidewell, C. (2019). Acta Cryst. E75, 1494-1506.]; Kiran Kumar et al. 2020[Kiran Kumar, H., Yathirajan, H. S., Harish Chinthal, C., Foro, S. & Glidewell, C. (2020). Acta Cryst. E76, 488-495.]), as well as those of a number of N-aroyl derivatives (Kiran Kumar, Yathirajan, Sagar et al., 2019[Kiran Kumar, H., Yathirajan, H. S., Sagar, B. K., Foro, S. & Glidewell, C. (2019). Acta Cryst. E75, 1253-1260.]). We have also reported the structures of some salts of N-(4-fluorophenyl)piperazine (4-FPP) (Harish Chinthal, Yathirajan, Archana et al., 2020[Harish Chinthal, C., Yathirajan, H. S., Archana, S. D., Foro, S. & Glidewell, C. (2020). Acta Cryst. E76, 841-847.]; Harish Chinthal, Yathirajan, Kavitha et al., 2020[Harish Chinthal, C., Yathirajan, H. S., Kavitha, C. N., Foro, S. & Glidewell, C. (2020). Acta Cryst. E76, 1179-1186.]). As a continuation of this study, we have now investigated a number of salts of the isomeric N-(2-methoxyphenyl)piperazine (2-MeOPP), which has been used as a building block in the synthesis of both 5-HT1A receptor ligands (Orjales et al., 1995[Orjales, A., Alonso-Cires, L., Labeaga, L. & Corcóstegui, R. (1995). J. Med. Chem. 38, 1273-1277.]) and dopamine D2 and D3 ligands (Hackling et al., 2003[Hackling, A., Ghosh, R., Perachon, S., Mann, A., Höltje, H. D., Wermuth, C. G., Schwartz, J. C., Sippl, W., Sokoloff, P. & Stark, H. (2003). J. Med. Chem. 46, 3883-3899.]) and also as a building block for the synthesis of derivatives exhibiting antidepressant-like activity (Waszkielewicz et al., 2015[Waszkielewicz, A. M., Pytka, K., Rapacz, A., Wełna, E., Jarzyna, M., Satała, G., Bojarski, A. J., Sapa, J., Żmudzki, P., Filipek, B. & Marona, H. (2015). Chem. Biol. Drug Des. 85, 326-335.]). Here we report the syntheses and structures of the salts (I)–(XI) (Figs. 1[link]–11[link][link][link][link][link][link][link][link][link][link]) formed between 2-MeOPP and eleven aromatic carboxylic acids, along with a redetermination of the salt (XII)[link] (Fig. 12[link]) formed with 2,4,6-trinitrophenol (picric acid) where the reported structure (Verdonk et al., 1997[Verdonk, M. L., Voogd, J. W., Kanters, J. A., Kroon, J., den Besten, R., Brandsma, L., Leysen, D. & Kelder, J. (1997). Acta Cryst. B53, 976-983.]; CSD refcode NEBGIK) shows signs of unmodelled disorder, and we report here also the structures of three acid salts (XIII)–(XV) (Figs. 13[link]–15[link][link]) formed with some aliphatic dicarboxylic acids. All of the salts (I)–(XV) were straightforwardly prepared by the acid–base reactions and subsequent crystallizations of equimolar mixtures of 2-MeOPP with the appropriate organic acid.
