Synthesis and characterization of aplysinopsin analogs

Three aplysinopsin analogs were synthesized by reacting 5-bromo-5-fluoro- and 6-bromoindole-3-carboxaldehyde with either creatinine or 2-imino-1,3-dimethyl-imidazolidin-4-one or 2-imino-1-methyl-3-ethylimidazolidin- 4-one Single crystal structures on 5-bromo-4′-de-N-methylaplysinopsin DMF solvate [from creatinine, space group P2₁/n, lattice parameters a = 13.117(3) Å, b = 8.6663(15) Å, c = 14.743(3) Å, β = 99.538(10)° at 173 K], 5-fluoroaplysinopsin DMF solvate [from 2-imino1,3-dimethyl-imidazolidin-4-one, space group P2₁/c, lattice parameters a = 11.114(3) Å, b = 19.118(2) Å, c = 8.503(2) Å, β = 112.290(7)°], and 6-bromoindole-3-carboxaldehyde (space group P2₁/n, lattice parameters a = 7.657(2) Å, b = 7.933(2) Å, c = 13.521(3) Å, β = 99.046(13)°) have been determined. Characterizations include spectrometric identifications employing IR, UV, HRMS, and ¹H and ¹³C NMR. 5-Bromo-4′-de-N- methylaplysinopsin and 5-fluoroapIysinopsin exist in the E configuration.