Ah, interesting use of that 4-phthalimidobutanal diethyl acetal... They aren't telling how they arrived at the 4-aminobutyraldehyde diethyl acetal though - is it commercially available, or can it be made from GABA easily??
4-Phthalimidobutanal Diethyl Acetal
4-Phthalimidobutanal diethyl acetal (7) was prepared by treating 4-aminobutyraldehyde diethyl acetal (8.33 g, 90% pure, 46.5 mmol) with N-carbethoxyphthalimide (10.73 g, 48.95 mmol) in water (75 mL) in the presence of NaHCO3 (3.93 g, 46.82 mmol) for 2 h at room temperature. The reaction mixture was extracted with CH2Cl2 (3x100 mL). The combined organic layers were washed with 5% NaHCO3 solution, dried over K2CO3, filtered, and concentrated to give relatively pure 7 (13.2 g, 45.3 mmol) as a colorless oil in 97% yield.
I believe that it would be interesting to test 5-Ethyl-DMT, this as it has been shown that 5,N,N-Trimethyltryptamine is active, at least by smoking it.