Synthesis of a novel exceedingly strong nonionic superbase

The synthesis of a novel superbase P(HNCH2CH2)(i-PrNCH2CH2)(2)N, 2a, is discussed. The conditions for the preparation and purification of H2NCH2CH2N(CH2CH2N-i-Pr)(2), 4a, starting from commercially available (H2NCH2CH2)(3)N (tren) were optimized. The existence of the novel zwitterion HP(N-CH2CH2)(i-PrNCH2CH2)(2)N+, 2b, was substantiated by NMR spectroscopy. The superbase 2a crystallizes from its melt when cooled slowly to -4 degrees C, and then remains as a solid at room temperature for several days. Hence it can be handled as a liquid or as a solid.