2,3-Dibromopropionaldehyde diethyl

A. 2,3-Dibromopropionaldehyde diethyl acetal. A 500-ml., three-necked, round-bottomed flask is equipped with a mechanical stirrer, a pressure-equalizing dropping funnel fitted with a calcium chloride drying tube, and a thermometer. The flask and dropping funnel are charged with 28.0 g. (0.5 mole) of freshly distilled acrolein and 80.0 g. (0.5 mole) of bromine, respectively. The acrolein is stirred rapidly and cooled to 0° in an ice-salt bath, then bromine is added at a rate such that the temperature is kept at... 

An early structural modification of FA and AP involved alkylation at C-9 and/or N-10. 10-MethylFA (447) [197] was prepared by reaction of 2,4,5-triamino-6-hydroxypyrimidine, 2,3-dibromopropionaldehyde and diethyl p-methylaminobenzoylglutamate (35), followed by alkaline hydrolysis (the Waller condensation). Analogous utilization of 2,2,3-trichlorobutyraldehyde and the requisite p-(JV-substituted amino)benzoylglutamate furnished (448a-c) (Scheme 3.88) [198]. The preparation of (450) by condensation of 2,4,5,6-tetraaminopyrimidine and the a-ketoacetal (449) was reported without details (Scheme 3.89) [199],... 

Compound (VIII.98), a folic acid analogue with a y-fluoro substituent in the side-chain was described first by Alekseeva e/ al. [281] and several years later by Bergmann and Chun-Hsu [282]. The synthesis of (VIII.98), as mixture of threo and erythro isomers, was achieved via the Waller method from V-(4-ami-nobenzoyl)-y-fluoroglutamic acid, 2,4,5-triamino-6(lif)-pyrimidinone, and 2,3-dibromopropionaldehyde, but the yield was low (5.6%). y-Fluoroglutamic acid, as a mixture of D- and L-enantiomers, was prepared from diethyl 2-fluoromalonate by condensation with ethyl 2-acetamidoacrylate followed by hydrolysis and decarboxylation in refluxing 12 M HCl, or from ethyl 3-chloro-2-hydroxypropanoate by a sequence consisting of (i) 0-t-butylation with CH2 = C(CH3)2, (ii) condensation with diethyl 2-acetamidomalonate, (hi)... 

Propionaldehyde, p-(4-t-butylphenyl)-a-methyl-. See 4-t-Butyl-a-methylhydrocinnamaldehyde Propionaldehyde, 2,3-dibromo-. See 2,3-Dibromopropionaldehyde Propionaldehyde, 2-methyl-2-(methylthio)-, O-(methylcarbamoyl) oxime. SeeAldicarb Propionaldehyde, 2-methyl-2-(methylthio)-, oxime. See Aldicarb oxime Propionaldehyde, 3-(methylthio)-. See3-Methylthiopropionaldehyde Propionamide, N,N-diethyl-2-(1-naphthyloxy)-. See Napropamide Propione. See Diethyl ketone Propionic acid... 

---