Synthesis and resolution of 2:5-dihydroxyphenylalanine

Study of the Pictet-Spengler reaction in aprotic media: synthesis of the .beta.-galactosidase inhibitor, pyridindolol

“…After removal of solvent, the resulting yellow solid was crystallized ffrom EtOH to give 29.0 g of white crystals of 6e (75% yield): mp 125 °C; IR (KBr) 3400 (s, NH) and 1725 (s, ester) cm-1; NMR (CDC13) 1.2 (t, 6 ), 3.0 (s, 1 H), 3.8 (s, 3 ), 3.6-4.0 (m, 4 H), 4.2 (m, 1 H), 4.5 (d, 1 H, J = 4 Hz), 7.0-7.6 (m, 10 ), 8.0 (s, 1 H); mass spectrum (70 eV). M+ at m/e 376 (38), 284 (100), 269 (50), 256 (88), 240 (88), 182 (50).…”

An N-Methylpyrrolidone-Diacetylene Complex. Its Use in the Isolation of Diacetylene

“…The diacetylene was synthesized by the treatment of 1,4-dichloro-2-butyne with base. 2 The temperature of the solution was reduced stepwise and the mixture was held at each temperature long enough to establish equilibrium between the solution and the solid complex which separated out. The supernatant liquid was then analyzed for diacetylene1 and the molality of diacetylene in the liquid phase and the mole % diacetylene precipitated in the complex were calculated.…”

(E)-4-(2,5-Dimethoxybenzylidene)-2-phenyl-1,3-oxazol-5(4H)-one

“…For the synthesis of this azalactone (which is used in the synthesis of other bioactive compounds), see: Bansal & Jain (1968); Gulland & Virden (1928); Hoseini & Jabar (2003); Khosropour et al (2008); Neuberger (1948); Radadia et al (2006); Solankee et al (2004); Yakovlev (1950). Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2009).…”