Methyl phenyl diketon

D.91) 1,2-Propanedione, 1-phenyl-, 1-phenylpropane-l,2-dione, methyl phenyl diketone, benzoyl methyl ketone, acetylbenzoyl [579-07-7] FEMA 3226... 

One of the older syntheses of ephedrine originates from Aladar Skita (1876-1953) in 1929 (Fig. 6.44). Methyl phenyl diketone is catalytically hydrogenated in presence of methylamine. Thus, ephedrine is produced in a single step, devoid of the other diastereomers of pseudoephedrine (the R,R- and S,S- enantiomers). [100]... 

Synonyms Acetyl benzoyl Benzoylacetyl Benzoyl methyl ketone Methyl phenyl diketone Methylphenylglyoxal Phenylmethyidiketone 3-Phenyl-2,3-propanedione 1,2-Propanedione, 1-phenyl- Pyruvophenone Empirical C9H8O2... 

This procedure represents a novel, convenient, and fairly general method for preparing y-aryl-/3-diketones. By this method the submitters have phenylated the dianion of 1-phenyl-1,3-butanedione (61%), 2,4-heptanedione (98%), 2,4-nonanedione (78%), 2,4-tridecanedione (53%), and 3,5-heptanedione (50%).6 Substituted diaryliodonium salts have also been used to produce l-(4-chlorophenyl)-2,4-pentadione (44%), 4-(4-methyl-phenyl)-l-phenyl-l,3-butanedione (44%), and l-(4-methyl-phenyl)-2,4-nonanedione (21%).6 Under these conditions no more than a trace, if any, of arylation at the a-position of the /3-diketones was observed by gas chromatography analysis. 

Phenyl- 1-trimethylsiloxyethene, the trimethylsilylenol ether of methyl phenyl ketone, added tellurium tetrachloride across the carbon-carbon double bond. Subsequent elimination of chlorotrimethylsilane produced bis[benzoylmethyl] tellurium dichloride. Addition to enols is also the first step in reactions of tellurium tetrachloride with monoketones and 1,3-diketones (p. 534, 535). 

Methyl-2-(4-methyl-phenyl)- E6a, 205 (1,4-Diketon + Lawesson-Reag.), 353 (Oxa - Thia)... 

The methyl phenyl di-ketone, sometimes called 1-phenyl, 1,2-propanedione, which would be the di-ketone used for condensation with methylamine and the subsequent hydrogenation in the presence of a catalyst to produce ephedrine, is known, as are certain other diketones. 

Methyl-[6.oxy-2.4.djiiiethyi-phenyl]-diketon-biB-ri-nitro-phenylhydiazon] 161139, n 206. 

CuH2qN,0j Methyl-[4-methoxy-phenyl]-diketon-bis- r4-nitro-phenyIhydiazon]... 

Pyrazoles are formed when the diazo compounds react with alkynes or with functionalized alkenes, viz. the enols of /3-diketones. Pyrazolenines (353 Section 4.04.2.2.1) are isolated from disubstituted diazomethanes. Many pyrazoles, difficult to obtain by other methods, have been prepared by this procedure, for example 3-cyanopyrazole (616) is obtained from cyanoacetylene and diazomethane (7iJCS(C)2i47), 3,4,5-tris(trifiuoromethyl)pyrazole (617) from trifluorodiazoethane and hexafluoro-2-butyne (8lAHC(28)l), and 4-phenyl-3-triflylpyrazole (618 R =H) from phenyltriflylacetylene and diazomethane (82MI40402). An excess of diazomethane causes iV-methylation of the pyrazole (618 R = H) and the two isomers (618 R = Me) and (619) are formed in a ratio of 1 1. 

The reaction of crotonaldehyde and methyl vinyl ketone with thiophenol in the presence of anhydrous hydrogen chloride effects conjugate addition of thiophenol as well as acetal formation. The resulting j3-phenylthio thioacetals are converted to 1-phenylthio-and 2-phenylthio-1,3-butadiene, respectively, upon reaction with 2 equivalents of copper(I) trifluoromethanesulfonate (Table I). The copper(I)-induced heterolysis of carbon-sulfur bonds has also been used to effect pinacol-type rearrangements of bis(phenyl-thio)methyl carbinols. Thus the addition of bis(phenyl-thio)methyllithium to ketones and aldehydes followed by copper(I)-induced rearrangement results in a one-carbon ring expansion or chain-insertion transformation which gives a-phenylthio ketones. Monothioketals of 1,4-diketones are cyclized to 2,5-disubstituted furans by the action of copper(I) trifluoromethanesulfonate. ... 

The five-coordinate complexes Ir(CO)(PPh3)2L, where HL = /3-diketone, A-benzoyl-A-phenyl-hydroxylamine, salicylaldehyde, 8-hydroxyquinoline, 2-hydroxybenzophenone, 2-hydroxy-8-methoxybenzophenone, were prepared from [Ir(CO)(PPh3)2Cl].632 The resulting compounds all underwent oxidative addition reactions with Br2. Reaction of [(cod)2IrCl]2 with N-substituted 3-hydroxy-2-methyl-4-pyridine gives the bichelated complex (389). 33... 

Casey et al. have studied the decarbonylation reactions of [cis-(OC)4M(MeCO)(PhCO)], in which M is Mn or Re (16,17). These complexes lose a carbonyl ligand to form five-coordinate intermediates of the type [(OC)3M(MeCO)(PhCO)]. Reversible methyl migration proceeds much more rapidly than does phenyl migration. In the course of these studies, a phosphine substituted rhena-/3-diketonate complex, [fac-(OC)3(Et3P)Re(MeCO) (PhCO)], was prepared. 

An interesting reaction takes place when diketones with the keto groups in positions 1,4 or more remote are refluxed in dimethoxyethane with titanium dichloride prepared by reduction of titanium trichloride with a zinc-copper couple. By deoxygenation and intramolecular coupling, cycloalkenes with up to 22 members in the ring are obtained in yields of 50-95%. For example, 1-methyl-2-phenylcyclopentene was prepared in 70% yield from 1-phenyl-1,5-hexanedione, and 1,2-dimethylcyclohexadecene in 90% yield from 2,17-octa-decanedione [206, 210]. 

The cycloaddition reactions of the unsymmetrical a-diazo-/3-diketone, 2-diazo-l-phenyl-l,3-butanedione 330, with diaryl imines 331 took place with high regioselectivity, affording exclusively the 6-methyl-5-phenyl-substituted 477-l,3-oxazin-4-ones 332 via the acetylphenylketene, generated by the thermal Wolff rearrangement of 330 (Equation 32) <2002HAC165>. 

KETENE, feef-butylcyano-, 55, 32 37, 38 Ketene 1 1-dimethylpropylcyano-, 55, 38 7-KETOESTERS, 58, 79, 81, 82 7-KETOESTERS TO PREPARE CYCLIC DIKETONES, 58, 83 KETONE terf-butyl phenyl, 55, 122 Ketone, methyl ethyl- 55, 25 Ketone, methyl vinyl, 56, 36 KETONES, acetylenic, 55, 52 Ketones, alkylation of, 56, 52 KETONFS aromatic, aromatic hydrocarbons from 55, 7... 

FROM a,a -DIBROMOKETONES AND ENAMINES 2,5-DI-METHYL-3-PHENYL-2-C Y CLOPENTEN-1 -ONE y-KETO-ESTER TO PREPARE CYCLIC DIKETONES 2-METHYL-1,3-CYCLOPENTANEDIONE, with the companion preparation y-KETOESTERS FROM ALDEHYDES VIA DIETHYL ARYLSUCCINATES 4-OXOHEXANOIC ACID ETHYL ESTER, which gives the procedure used to prepare the needed... 

An exceptional cyclization was observed in the case of 2,3,4-tri-phenyl-1,5-diketone 57b, giving 65°7o of 2//-thiopyran 56 in contrast to the expected behavior of the 3-methyl analog 57a, which afforded 72% of 4H-thiopyran 58.IOSa The origin of 57 might be due to isomerization of a primary product. 

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