1- propane-1,3-dione

Jones RDG (1976) The crystal structure of the enol tautomer of 1,3-diphenyl-1,3-propane-dione (dibenzoylmethane) by neutron diffraction. Acta Cryst B32 1807-1811... 

When a metal ion such as nickel (II) is absent, thiazoles and mercaptals are formed. Such reactions have been carried out in which the diketone was biacetyl, 2,3-pentanedione, 2,3-octanedione, l-phenyl-l,2-propane-dione, and 1,2-cyclohexanedione (51). In like manner, the tris complexes of W,W -dimethyl-2,3-butane diimine with iron(II), cobalt(II), and nickel(II) may be prepared from methylamine and biacetyl when the appropriate metal ion (27j 28j 41) is present. Replacing methylamine with hydroxylamine causes the formation of a-dioximes (13). 

An initial pinacol dimerization is responsible for the formation of 1,3,5,7-tetraphe-nyl-2,4,6-trioxatricyclo[3.3.0.1]nonane during the electrolysis of 1,3-diphenyl-1,3-propane-dione in slightly acidic solution [2]. 

Lios and Duddeck ° studied substituted l-(2-hydroxyphenyl)-3-naphthyl-l,3-propane-diones. The OH resonance falls in the range 93-102 ppm. The higher value was found in a derivative with a methoxy group meta to the OH group in question. The position of the tautomeric equilibrium could also influence the chemical shifts. 

With the additive 2-oxazoUdinone in DMSO to assist Cul at 120°, A-arylation of amides (lactams) is readily performed. A more commonly used ligand is 1,10-phenanthroline, as it is applied also to form iV-(aryl)alkoxyamines from RNHOR. In A-arylation of iV-heterocycles (indole, pyrrole, imidazole, pyrazole,...), l,3-di(2-pyridyl)-l,3-propane-dione appears to be a useful ligand for Cul. ... 

Photolysis, apparatus for, 55, 17 Phthalimide, N-amino- [ 1//-Isoindole-1,3-(2//)-dione, 2-amino-, 55, 115 Potassium rew-butoxide [2-Propanol, 2-methyl-, potassium salt], 55,12, 13 Potassium iodide, 55, 71 Potassium permanganate [Permanganic acid, potassium salt], 55,68 Propane, 2,2 dimethyl 1 phenyl, 55, 112 Propane, 2 isocyano-2-methyl-, 55, 96... 

Examples of reactions involving replacement and cyclization are the long-known preparation of thiophenes (89) from 1,4-diketones, and the formation of l,2-dithiole-3-thione (90) from the salicylate ester analog (91).120 In the latter instance, oxidative cyclization with formation of an S—S bond has occurred this is a common feature of these reactions, particularly if such a link is needed to complete a five-membered ring. Another example of this aspect is afforded by the reaction of the propane-1,3-dione derivatives (92) which yield 3,5-diaryl-1,2-dithiolylium salts (93) when heated with phosphorus pentasulfide in carbon disulfide, followed by perchloric acid.121... 

Up to about 10 percent of crs-stilbene was obtained when trimethyl-dioxetane 129 was decomposed in the presence of trans-stilbene 182) the electronic excitation energy of the excited carbonyl compounds formed in the cleavage of 129 (see Section V.) was transferred to trans-stilbene, so effecting the photochemical trans-cis isomerization. When bis (2.4-dinitrophenyl) oxalate reacted with hydrogen peroxide (see Section V. C. in the presence of o-tolyl-propane-1.2-dione 130, 2-methyl-2-... 

In the case of methyl vinyl ketone (MVK), similar reactivity is observed. Exposure of MVK (150 mol%) and p-nitrobenzaldehyde to basic hydrogenation conditions provides the corresponding aldol product in good yield, though poor dia-stereoselectivity is observed [24a]. Remarkably, upon use of tris(2-furyl)phos-phine as ligand and Li2C03 as basic additive, the same aldol product is formed with high levels of syn-selectivity [24 e]. Addition of MVK to activated ketones such as l-(3-bromophenyl)propane-l,2-dione is accomplished under similar con-... 

The condensation products (1 1) of pentane-2,4-dione and 1,3-diphenyl-propane-1,3-dione with thiosemicarbazide, 4-methylthiosemicarbazide, and aminoguanidinium nitrate were formed (86KGS128 87ZOB584 90-KGS1260) as the cyclic isomers 78, which sometimes readily underwent dehydration to the corresponding pyrazoles. 

Primary alcohols were oxidised to aldehydes and (less readily) secondary alcohols to ketones by Ru(N0)Cl(salen = )/03//UV (incandescent or halogen lamp), hi competitive experiments between 1- and 2-decanol or benzyl alcohols only the primary alcohol was oxidised [827]. With Ru(NO)Cl(salen )/(Cl2pyNO) or TMPNO or Oj/C H /UV (TMPNO=tetra-methylpyridine-iV,iV -oxide) racemic secondary alcohols were asymmetrically oxidised to ketones [828]. A Ru(NO)(salen " ) complex was used as Ru(N0)Cl(salen " )/02/UV/CgH3Cl to oxidise racemic secondary alcohols to the ketones in the presence of l,3-bis(p-bromophenyl)propane-l,3-dione e.e. of 55-99% were achieved [829], Chiral Ru(NO)Cl(salen ) complexes were made... 

Prop-Z-en-l-al, 3 (2 furyl) Sd (roasted Propan l 2 dione, l (2 furyl) Sd (roasted... 

Acetyl-4-hydroxy-2H-l,3-thiazine-2,6-diones 61 react with primary amines to give Schiff bases 49. These products are stable under conditions of excess base and prolonged heating in boiling propan-2-ol (Equation 9) <2005RJC134, 2003TL5279>. 

The vapor-phase pyrolysis (680°C) of 2-diazoindane-l,3-dione, followed by trapping of the intermediate ot-oxo ketene 11 in alcohols such as methanol, propan-2-ol or tert-butyl alcohol, gave 31-51 % yields of the corresponding j3-oxo esters 12.49... 

Thioketals are readily prepared by treating the corresponding ketone with ethanedithiol and propane-1,3-dithiol. The 12-ketone fails to react with monothiols such as ethanethiol or thiophenol92 or with the bulkier 1-phenylethane-1,2-dithiol or tetralin-2,3-dithiol.93 The A9(11)-12-ketone readily forms a thioketal on reaction with ethanedithiol.28 The selective protection of 11,12-diones (83) as the 12-monothioketals (84) is possible due to the poor reactivity of the 11-ketone.46,10... 

The hexahydropyrimidine (58), formed from l-phenylpropane-l,2-dione and propane-1,3-diamine, is an excellent precursor for the a-diimine macrocyclic complexes (60), presumably via the amino ketone (59) (Scheme 36).126 In this case, intramolecular cyclization of (59) to (58) is reversible, so that the metal ion can exert a thermodynamic template effect in formation of the complex (60). This represents a further example of a long-known phenomenon in which a metal ion can stabilize an a-diimine structure by virtue of the formation of stable five-membered chelate rings. Many 2-hydroxy- or 2-mercapto-amines undergo reaction with a-dicarbonyl compounds to yield heterocyclic compounds rather than a-diimines. However, in the presence of suitable metal... 

The decomposition of propanal, CH3CH2CHO, is a free radical chain process. The major products are C2H6 and CO. There are three minor products, butane, pentan-3-one and hexan-3 4-dione. Of these pentan-3-one is the most abundant. Pentanal is produced in trace amounts while H2 is found as a very minor trace product. The reaction is found to be first order at high pressures moving to second order at low pressures. Deduce a mechanism to fit these facts. 

The same experimental procedure was used for further N-alkylation reactions of 2,4-bis(trimethylsilyloxo)thieno[3,2-d]pyrimidine-2,4-diones 271. Thus, reaction of 271 with 2-acetoxyethyl acetoxymethyl ether, 2-(acetoxymethoxy)propane-l,3-dibenzoate, and benzyloxymethyl acetate gave the respective 1- and 3-alkylated derivatives 274 and 275, 276 and 277, and 278 and 279 (90MI1 94JHC305 94MI2, 94MI3). ... 

Two synthetic routes for 3-[4-[4-(2-methoxyphenyl)piperazin-l-yl]butyl]-thieno[3,4-d]pyrimidine-2,4-dione 316 were described by Russell et al. (90JHC1761). Carbamate 310a, prepared by treating a mixture of amine hydrochloride 309 and ethyl chloroformate with dilute sodium hydroxide, was reacted with 4-[(2-methoxyphenyl)piperazin-l-yl]butanamine 313 in the presence of trimethylaluminum/toluene. The yield of 316 was a modest 20%. However, when bromobutyl urea 314 was heated with l-(2-methoxyphenyl)piperazine hydrochloride 315 in the presence of sodium bicarbonate and sodium iodide in propan-2-ol, compound 316 was obtained in 84% yield. The first route was also used to synthesize thieno[3,4-d]py-rimidine-2,4-dione 312 in 36% yield from 310a and 4-(2-methoxyphenyl)-1-piperazinethanamine 311. 

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