Dichloro-methane formaldehyde

Synthesis of isomeric chiral protected (63 )-6-amino-hexahydro-2,7-dioxopyrazolo[l,2- ]pyrazole-l-carboxylic acid 280 is shown in Scheme 36. Crude vinyl phosphonate 275, obtained by treatment of diethyl allyloxycarbonylmethyl-phosphonate with acetic anhydride and tetramethyl diaminomethane as a formaldehyde equivalent, was used in the Michael addition to chiral 4-(f-butoxycarbonylamino)pyrazolidin-3-one 272. The Michael addition is run in dichloro-methane followed by addition of f-butyl oxalyl chloride and 2 equiv of Huning s base in the same pot to provide 276 in 58% yield. The allyl ester is deprotected using palladium catalysis to give the corresponding acid 277, which is... 

The selectivity to formaldehyde increased with the content of dichloro-methane in the stream. 

Ammonium pyrrolidine dithiocarbamate (APDC) An aqueous solution containing 0.1 mol/L APDC is prepared by dissolution in pure water. Contaminating zinc is removed from this solution by extraction with a solvent such as trichlorotrifluoroethane, dichloro-methane or formaldehyde. The solvent itself is first cleaned by shaking with acid. 

Two isomers are described in the literature 2-Methyl-l,2,3-propanetriol or f3-Methylgylcerol, CH2(OH).C(CH3XOH).CH2.OH, col vis liq, bp 115-20° at 1.6mm. d 1.186 at 20°, nD 1.4730 at 20°, can best be prepd by hydration of /S-methyl-glycidol(2,3-epoxy- 2-metiiyl-l-propanol), and can be prepd directly from either dichloro-tert-butyl alcohol or /3-methylglycerol monochlorohydrin(Ref 2). See also Refs 1,4 5) and 2-(Hydroxymetby[)-l,3-propanediol or Trimethylol Methane, CH2(OH).CH(CH2OH)2 was prepd by Fujii(Ref 3) from a mixt of acetaldehyde formaldehyde(10 25 mol) heated with Ca(OH)2 and the product reduced with H in the presence of Ni... 

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