J aminoketones

Sulfuric acid S-Heterocyclics from ketomercaptans s. U, 681 4H-l,3-Thiazine-2>thiols from j -aminoketones via j -ketodithiocarbamic acids s. 12, 691 H SOi... 

Gadhwal, S., Baruah, M., Prajapati, D. and Sandhu, J.S., Microwave-assisted regioselective synthesis of p-aminoketones via the mannich reaction, Synlett, 2000, 3, 341—342. 

Grob-type fragmentations induced by nucleophilic attack of Nhfr on the carboxyl group of quaternary /J-aminoaldcliydes and jS-aminoketones (119) have been reported (Scheme 14)." /V-(2-lmino-1 -oxopropyl)glycinc is fonned as an intennediate in the base-catalysed decomposition of (A -X)-Ala-Gly.100... 

NaOH added with stirring at -10° to the startg. a-aminoketone hydrodiloride in water-ether, then ethereal cyanogen chloride cooled to -40° added dropwise, stirred 2 hrs. at -10 to -5° and 5-9 hrs. at room temp. product. Y 69.2% 70.6% with cyanogen bromide. F. e. s. J. Schuart and H. K. Muller, Pharmazie 30, 82 (1975). 

A soln. of startg. (3-chloroketimine in /cr/-butanol treated with 2 eqs. KOBu-r, stirred under reflux for 12 h, after cooling the mixture diluted with pentane, and stirred for 1 h 2-methylene-3,3-dimethyl-l-phenylazetidine. Y 90%. The method is restricted to N-aryl-derivs., N-benzyl-derivs. affording cyclopropanes (Synth. Meth. 42, 952) and N-alkyl-derivs. giving p-aminoketones. F.e. inch spiro and bicyclic compds. s. P. Sulmon et al., J. Org. Chem. 53, 4462-5 (1988). 

Stereospecific reduction. NaBH4 added with stirring at 25° to a soln. of 9a-fluoro -16a- methyl -17,20 20,21- bis (methylenedioxy) -11- oxopregn -4- eno [3,2-c] -pyrazole in dimethylformamide containing water, after 4 hrs. ice-cooled, excess reagent decomposed with N HCl, and the product converted to its hydrochloride 9a-fluoro-ll) -hydroxy-16a-methyl-17,20 20,21-bis (methylenedioxy)-pregn-4-eno[3,2-c] pyrazole hydrochloride. Y 86.2%. R. Hirschmann et al., J. Med. Chem. 7, 352 (1964) aminoalcohols s. T. Chiemprasert, H.-J. Rimek, and F. Zymalkowski, A. 685, 141 (1965) stereospecific reduction of a-aminoketones s. A. Ichihara et al.. Bull. Chem. Soc. Japan 38, 1158 (1965). 

See, for instances (a) S. Santra, R R. Andreana, Org. Lett. 2007, 9, 5035-5038. A one-pot, microwave-influenced synthesis of diverse small molecules by multicomponent reaction cascades, (b) M. Presset, Y. Coquerel, J. Rodriguez, Org. Lett. 2009, 11, 5706-5709. Microwave-assisted domino and multi-component reactions with cyclic acyUcetenes expeditious syntheses of oxazinones and oxazindiones. (c) W.-J. Hao, B. Jiang, S.-J. Tu, X.-D. Cao, S.-S. Wu, S. Yan, X.-H. Zhang, Z.-G. Han, F. Shi, Org. Biomol. Chem. 2009, 7,1410-1414. A new mild base-catalyzed Mannich reaction of hetero-arylamines in water highly efficient stereoselective synthesis of 3-aminoketones under microwave heating, (d) P. Nun, J. Martinez, F. Lamaty, Synthesis 2010, 2063-2068. Microwave-assisted neat procedure for the Petasis reaction. 

An aq. soln. of NaHCOg added to a stirred soln. of / -ionone oxime (prepared from / -ionone, hydroxylamine hydrodiloride, and K-carbonate in water-ethanol) in tetrahydrofuran, protected from light, KI and iodine in water added, and refluxed 4 hrs. -> isoxazole deriv. (Y 91%) mixed with liq. NHg, tetrahydrofuran, and rerf-butanol, treated with Na until the soln. remains dark blue, stirred 15 min., and the crude / -aminoketone refluxed 24 hrs. with a trace of p-toluene-sulfonic acid in toluene / -damascone (Y 84%). F. e. s. G. Budii and J. C. Vederas, Am. Soc. 94, 9128 (1972) s. a. K. H. Sdiulte-Elte, B. L. Muller, and G. Ohloff, Helv. 56, 310 (1973). 

Dimethylamino - a - methylpropiophenone and dibenzoyl - (—) - tartaric acid monohydrate dissolved in acetone, stirred until crystallization begins and for an additional 18 hrs., the solid collected and washed with acetone, the combined filtrate coned, with repeated collection of additional product ( —)-j -di-methylamino-a-methylpropiophenone acid dibenzoyltartrate (Y 94%) treated with aq. NHg, extracted with ether, dried with anhydrous MgS04, and acidified with dry HCl ( —)-/ -dimelhylamino-a-methylpropiophenone hydrochloride (Y 94%).—Concentration of the filtrate from the resolution causes racemization of the soluble diastereoisomeric salt and affords a nearly quantitative yield of the insoluble salt. Dibenzoyl-( + )-tartaric acid yields the insoluble salt with the ( + )-aminoketone. A. Pohland, L. R. Peters, and H. R. Sullivan, J. Org. Ghem. 28, 2483 (1963) cf. W. Theilacker, P. Braune, and G. G. Strobel, B. 97, 880 (1964). 

A. Bunescu, C. Piemontesi, Q. Wang, J. Zhu, Heteroannulation of arynes with N-aryl a-aminoketones for the synthesis of unsymmetrical N-aryl-2,3-disubstituted indoles an aryne twist of Bischler-Mohlau indole synthesis, Chem. Commun. 49 (2013) 10284-10286. 

Millet, R., Traff, A. M., Petrus, M. L., and Backvall, J. E. (2010). Enantioselective synthesis of syn- and anti-l,3-aminoalcohols via beta-aminoketones and subsequent reduction/ dynamic kinetic asymmetric transformation. /. Am. Chem. Soc., 132,15182-15184. 

Pyrroles. Equimolar amounts of a-aminopropiophenone hydrochloride, dimethyl acetylenedicarboxylate, and Na-acetate refluxed 10 min. in methanol then 30 min. in the presence of a little HGl dimethyl 5-methyl-4-phenyl-pyrrole-2,3-dicarboxylate. Y 81%.—A weak base is used as catalyst for the Michael addition to prevent dimerization of the a-aminoketone. F. e., also isolation of the intermediate, and quinolines, s. J. B. Hendrickson and R. Rees, Am. Soc. 83, 1250 (1961). 

---