Originally posted by trilobite:
Here is the full abstract. Note that the researchers do not prepare 1-phenyl-2-propyn-1-one at all, obviously PhCOEt really IS propiophenone, prepared
in several steps from benzaldehyde.
Acetylenic alcohol and its derivatives. IV. Synthesis of propiophenone and 3,4-methylenedioxypropiophenone. Hirao, Ichiro. Ono Pharmaceutical Co.,
Yakugaku Zasshi (1953), 73 1224-6.
Abstract
BzH (4 kg.) in 7 l. 90% MeOH in an autoclave with C2Cu2 is adjusted to pH 7.8 with NaOH, charged to 10-15 atm. with C2H2, heated 4-5 hrs. at 120°,
and the product extd. with Et2O and distd. to give PhCH(OH)C.tplbond.CH (I), b14 114-16°; benzoate, m. 81-3°; phenylcarbamate, m. 73-5°. Catalytic
reduction of 60 g. I in 150 ml. MeOH with 5 g. Raney Ni and 60 atm. H 30 min. at 40° gives 58 g. PhCH(OH)Et (II), b15 108-10°; similarly is prepd.
3,4-CH2O2C6H3CH(OH)Et (III), b12 143-4°. II (39 g.) added dropwise to 45 g. K2Cr2O7, 60 g. H2SO4, and 400 ml. water, the mixt. stirred 1 hr. at
25-30°, and the product extd. with Et2O and distd. gives 36 g. PhCOEt, b7 85-6°; semicarbazone, m. 176-7°; similarly is prepd. 3,4-CH2O2C6H3COEt,
b4 124-7°, m. 38-9°. A mixt. of 50 ml. 75% MeOH and 0.6 g. H2SO4 at 60° treated with 0.6 g. HgSO4 and 26 g. PhCOEt in 20 ml. MeOH, heated 5-6 hrs.
at 60°, the product neutralized with Na2CO3, the MeOH removed, and the residue extd. with Et2O and distd. gives 18 g. BzCOMe, b13 151-2°;
disemicarbazone, m. 226-30°.
Here is a P2P synth by the same researcher which uses the alkyne hydration reaction on 1-phenyl-2-propyn-1-ol.
Phenylethynylcarbinol and its derivatives. II. Synthesis of phenylacetone. Hirao, Ichiro. Osaka Univ., Nippon Kagaku Kaishi (1921-47) (1953), Ind.
Chem. Sect. 56 265-6.
Abstract
Com. PhCH(OH)C.tplbond.CH was hydrated with H2SO4 to PhCH(OH)COCH3, which was hydrogenated with Raney-Ni catalyst by H of 50 atms. in an autoclave at
room temp. The white crystals obtained correspond to 1,2-dihydroxy-1-phenylpropane (I) of m.p. 91-92°; yield, 95%. PhCH2Ac was prepd. by treating of
I with H2SO4, oxalic acid, H3PO4, etc. at the b.p. of the soln.; yield, approx. 73%
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