2- propiophenone

Add 5 ml. (5 g.) of acetophenone, 1-25 g. of finely powdered paraformaldehyde, and 3 5 g. of dry dimethylamine hydrochloride to 8 ml. of absolute ethanol, and then boil the mixture under reflux for 1-5 hours. Filter the solution (which is now almost entirely clear) through a preheated filter-funnel, and cool the filtrate in ice-water with stirring. The propiophenone hydrochloride rapidly separates as white crystals filter oflF the crystals at the pump and recrystallise from a small quantity of ethanol m.p. 155-156°. Yield, 2 5 g. 

An improved yield is obtained by the following process. Add a mixture of 75 g. (70-5 ml.) of propionyl chloride and 90 g. (103 ml.) of sodium-dried A.R. benzene to a vigorously stirred suspension of 75 g. of finely-powdered anhydrous aluminium chloride in 100 ml, of dry carbon disulphide, Then introduce more of the aluminium chloride (about 15 g.) until no further evolution of hydrogen chloride occurs. The yield of propiophenone, b.p. 123°/25 mm., is about 90 g. 

Reduction of the ethylenic compound gives a ketone, propiophenone (III), with one more methylene group than the ketone used in the original preparation ... 

Benzoylpropionitrile. To a mixture of 21 4 g. of p dimethylamino propiophenone hydrochloride, 13 0 g. of potassium cyanide in a 500 ml. flask, add 260 ml. of boiling water heat the heterogeneous mixture under reflux for 30 minutes. Part of the dimethylamine, which is eliminated in the reaction, distils collect this in dilute hydrochloric acid. Cool the reaction mixture in ice the oil sohdifies and crystals form from the aqueous layer. Collect the solid (crude p benzoylpropiouitrile, 10-5 g.) by suction filtration and recrystallise it from benzene - light petroleum (b.p. 40-60°) it separates as almost colourless blades, m.p. 76°. 

The success of the last reaction depends upon the inertness of the ester carbonyl groups towards the organocadmium compound with its aid and the use of various ester acid chlorides, a carbon chain can be built up to any reasonable length whilst retaining a reactive functional group (the ester group) at one end of the chain. Experimental details are given for l-chloro-2-hexanone and propiophenone. The complete reaction (formation of ketones or keto-esters) can be carried out in one flask without isolation of intermediates, so that the preparation is really equivalent to one step. 

Propiophenone. Prepare a solution of diphenyl-cadmium in 110 ml. of dry benzene using 4 9 g. of magnesium, 32 4 g. of bromobenzene and 19 5 g. of anhydrous cadmium chloride. Cool the solution to 10°, and add during 3 minutes a solution of 14 -8 g. of propionyl chloride (b.p. 78-79°) in 30 ml. of dry benzene use external coohng with an ice bath to prevent the temperature from rising above 40°. Stir the mixture for 2 hours at 25-35°. Work up the product as detailed above except that 6 per cent, sodium carbonate solution should replace the saturated sodium bicarbonate solution. The yield of propiophenone, b.p. 100-102°/16 mm., is 17 6 g. 

Not-Strike may have seen. But what Dr. Quack did that SWINS did not was use the bisulfite test with positive results. What does that mean It means that some doublebonded oxygen was formed, unless Dr. Quack was fibbing to us, It cannot have been a propiophenone (don t ask) because propiophenones cannot form the bisulfite addition product. Could an aldehyde have formed (don t ask) Maybe. But highly unlikely considering the mechanism of the reaction. 

Efforts directed to prepare MDP2P via this method results in good yields of a ketone with properties completely dissimilar to MDP2P, and is probably the propiophenone, formed by migration of the nitro group during the hydrolysis. 

The 4-arylthiazoles are obtained from phenacylbromide and its substituted derivatives (in 40 to 87% yields) (264, 335, 646), and 4-phenyl-5-methylthiazole (129, 641) and 4,5-diphenylthiazole (519) from -bromo-propiophenone and desylchloride, respectively. 

Aromatic ketones of industrial significance include acetophenone, propiophenone, and benzophenone. 

Propiophenone. Propiophenone [93-55-0] (ethyl phenyl ketone) is a colorless Hquid with a flowery odor. It can be prepared by the Friedel-Crafts reaction of benzene and propionyl chloride in the presence of aluminum chloride (346), or by the catalytic reaction of benzoic acid and propionic acid in the presence of water (347). Propiophenone is commercially available (348), and is sold in Japan at 2700 Y/kg (349). It is used in the production of ephedrine, as a fragrance enhancer, and as a polymerization sensitizer. 

The reaction of propiophenone with thionyl chloride in pyridine provides 3,4-diben-zoylthiophene (79H(l2)46i). The boron trifluoride catalyzed reaction of benzophenone with f-butyl isocyanide gives an indole derivative (Scheme 84b) (67TL3881). Another... 

The reaction of a dibromochalcone with hydroxylamine hydrochloride in pyridine gave three products with the expected 2-isoxazoline product as the predominate compound. A ring bromination product and an isoxazole were also isolated (70UC796). The reaction of hydroxylamine with /S-thiosulfates of propiophenone at reflux produced 3-phenyl-2-isoxazo-line (455). At room temperature a bis-Michael product (456) was produced. The reaction with N -phenylhydroxylamine yielded a mono-Michael type product (457) (74CPB1990). 

Cls-1 -dlmethyl-3-phenylazlridlne (2) To a coofed and well stirred suspension of LAH (3 S g, 0 1 mol) m Et20 (100 mL) was added dropwise a solution of 2 2-dichloro-N methyl propiophenone imme 1 (10 8 g, 0 05 mol) m Et20 (100 mL) After overnight reflux the mixture was poured with caution onto ice water aixf the product extracted with Et20 Evaporation ot the solvent gave 8 21 g of 2 (84%), bp 79 82°C... 

In 1934, French chemist Hoch reported that the action of phenylmagnesium bromide on the oxime of propiophenone (3) at elevated temperature gave two products. One was aziridine 4 and the other was erroneously assigned as hydroxylamine 5. In the subsequent years (1939 onward), Campbell at the University of Notre Dame determined that the purported hydroxylamine 5 was actually P-hydroxylamine 6. The scope of the Grignard reagents was extended to both aryl and aliphatic Grignard reagents. 

The use of acid chlorides instead of acid anhydrides has also been described. Wittig and coworkers converted propiophenone 31 to chromone 32 in 50% yield with chloroacetyl chloride in the presence of sodium chloroacetate at 190 C. Despite the acid chloride s increased reactivity, a high temperature was still required. 

In the realm of natural product synthesis, Kepler and Rehder utilized the K-R reaction to synthesize ( )-calanolide A (56), a potent non-nucleosidal human irmnunodeficiency virus (HIV-1) specific reverse transcriptase inhibitor. Propiophenone 57 was allowed to react with acetic anhydride in the presence of sodium acetate to afford benzopyranone 58 in 56% yield subsequent deacetylation of 58 gave 59. Flavone 59 was then transformed to ( ) calanolide A (56) over several steps. 

Coumaran-2,3-semidione was prepared by treatment of eoumaran-2,3-dione with the enolate anion of propiophenone in DMSO (70JA2762). 

Introduction of branching in the side chain is apparently consistent with retention of the antiparkinson activity. Bro-mination of propiophenone gives the brominated ketone, 33. Dis-... 

Condensation of the substituted phenethyl bromide, 18, with piperazine can be stopped at the monosubstituted amine (19). Reaction of this amine with propiophenone and formaldehyde in a Mannich reaction affords eprazinone (20) an antitussive agent. 

Self-condensation of the substituted propiophenone, 15, by the pinacol reaction proceeds to give the glycol, 16, as the meso isomer. (If it is assumed that the transition state for this reaction resembles product, this stereoselectivity can be rationalized on the grounds of steric interaction compare A, which leads to the observed product, with B.) Dehydration under very specialized conditions (acetyl chloride, acetic anhydride) affords the bisstyrene-type diene (17). Removal of the acyl groups by means of base affords the synthetic estrogen, dien-... 

The initial steps involve reacting benzyl chloride with 4-hydroxy propiophenone. The benzyl-oxypropiophene thus obtained is first brominated and then reacted with 4-benzylpiperidine to give 1-(p-benzyloxyphenyl)-2-(4-benzyl-piperidino)propan-1-one. 

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