Methyl-P-naphthyl ketone

Steam distil from a 1 - 5 litre three-necked flask until the odour of nitrobenzene is no longer perceptible in the distillate (6-12 hours). Extract the cold residue with three 100 ml. portions of ether, dry the combined extracts with anhydrous magnesium sulphate, and distil oflF the ether. The residue solidifies and consists of almost pure methyl P-naphthyl ketone, m.p. 52° the yield is 30 g. Upon recrystallisation from glacial acetic acid, the m.p. is raised to 54°. 

Prepare a solution containing about 100 g, of potassium hypochlorite from commercial calcium hypochlorite ( H.T.H. ) as detailed under -Dimethylacrylic Acid, Section 111,142, Note 1, and place it in a 1500 ml. three-necked flask provided with a thermometer, a mechanical stirrer and a reflux condenser. Warm the solution to 55° and add through the condenser 85 g, of p-acetonaphthalene (methyl p-naphthyl ketone) (1). Stir the mixture vigorously and, after the exothermic reaction commences, maintain the temperature at 60-70° by frequent cooling in an ice bath until the temperature no longer tends to rise (ca. 30 minutes). Stir the mixture for a further 30 minutes, and destroy the excess of hypochlorite completely by adding a solution of 25 g. of sodium bisulphite in 100 ml. of water make sure that no hypochlorite remains by testing the solution with acidified potassium iodide solution. Cool the solution, transfer the reaction mixture to a 2-litre beaker and cautiously acidify with 100 ml. of concentrated hydrochloric acid. Filter the crude acid at the pump. 

The commercial product, m.p. 53-55°, may be used. Alternatively the methyl p-naphthyl ketone may be prepared from naphthalene as described in Section IV, 136. The Friedel - Crafts reaction in nitrobenzene solution yields about 90 per cent, of the -ketone and 10 per cent, of the a-ketone in carbon disulphide solution at — 15°, the proportions are 65 per cent, of the a- and 35 per cent, of the isomer. With chlorobenzene as the reaction medium, a high proportion of the a>ketone is also formed. Separation of the liquid a-isomer from the solid -isomer in such mixtures (which remain liquid at the ordinary temp>erature) is readily effected through the picrates the picrate of the liquid a-aceto compound is less soluble and the higher melting. 

SYNS P-ACETONAPHTHALENE ACETONAPHTHONE p-ACETONAPHTHONE 2-ACETONAPHTHONE p-ACETYLNAPHTHALENE 2-ACETYLNAPHTHALENE FEMA No. 2723 METHYL-p-NAPHTHYL KETONE (FCC) METHYL-2-NAPHTHYL KETONE p-METHYL NAPHTHYL KETONE l-(2-NAPHTHALENYL)ETHANONE p-... 

METHYL 1-NAPHTHYL KETONE see ABC475 METHYL-2-NAPHTHYL KETONE see ABC500 METHYL a-NAPHTHYL KETONE see ABC475 a-METHYL NAPHTHYL KETONE see ABC475 P-METHYL NAPHTHYL KETONE see ABC500 METHYL-p-NAPHTHYL KETONE (FCC) see ABC500 N-METHYL-N-(1-... 

Aryl methyl ketones give generally high yields of acids on treatment with hypohalites [6SS, 696,698, 736. The reaction of 1,3,5-triacetylbenzene and sodium hypochlorite results in a 94% yield of trimesic acid [655], and that of methyl p-naphthyl ketone and sodium hypochlorite gives an 87-88% yield of p-naphthoic acid [695]. 4-Acetyl-4 -methoxybiphenyl is converted... 

Ci2H10O, Mr 170.21, 6pi.7kPa 171-173 °C, df 1.171, ng° 1.6752, has been identified in some essential oils. It smells like orange blossom and is a colorless crystalline solid (mp 56 °C). It is usually prepared by Friedel-Crafts acetylation of naphthalene (with acetyl chloride, acetic anhydride, etc.) in the presence of aluminum chloride. In polar solvents (e.g., nitrobenzene), the percentage of the simultaneously formed a isomer is lower. Methyl P-naphthyl ketone is used in eau de cologne, soap perfumes, and detergents. It is a good fixative. 

Distil the dry (anhydrous magnesium sulphate) nitrobenzene solution under reduced pressure. Nitrobenzene passes over at 95-100 /16 mm. and the temperature then rises rapidly to 170715 mm. collect the fraction of b.p. 170-180 /16 mm. Transfer whilst still liquid to a porcelain basin it solidifies on cooling. Spread it on a porous tile to absorb the small proportion of liquid a-ketone which is present the resulting yield of crude methyl p-naphthyl ketone, m.p. 40-42°, is 50 g. Two recrystallisations from glacial acetic acid (or from glacial acetic acid - water) give the almost pure p-ketone, m.p. 63 . 

Synonyms p-Acetonaphthalene Acetonaphthone 2-Acetonaphthone p-Acetonaphthone 2-Acetylnaphthalene P-Acetyinaphthalene Methyl naphthyl ketone Methyl 2-naphthyl ketone Methyl p-naphthyl ketone p-Methyl naphthyl ketone 1-(2-Naphthalenyl) ethanone 2-Naphthyl methyl ketone P-Naphthyl methyl ketone Orange crystals Empirical C12H10O... 

Methyl p-naphthyl ketone p-Methyl naphthyl ketone. See 2 -Acetonaphthone N-Methyl-a-naphthylurethan. See Carbaryl Methyl neopentanoate. See Methyl pivalate Methyl Niclate . See Nickel dimethyidithiocarbamate Methyl nicotinate... 

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