Methylacetophenone

Methylacetophenone is first reacted with paraformaldehyde and then with pyrrolidine to give p-methyl-CJ-pyrrnlidinopropiophenone. 

From the diverse examples on Hantzsch syntheses reported, the reaction of 2-bromo-4 -methylacetophenone and l-acetyl-2-thiourea was exemplarily chosen to be represented here [10]. 

C9H10CINO2 5-Chloro-2-hydroxy-4- methylacetophenone oxime ExQ-action-photometric Gravimettic V V 3... 

Bromo-4-methylacetophenone from aluminum chloride catalyzed bromination of 4-methylacetophe-none, 40, 9... 

With regard to the synthesis of celecoxib (1), several routes were described in the 1995 patent by G. D. Searle As shown in Scheme 1, dione 7 was prepared by the Claisen condensation of 4-methylacetophenone with ethyl trifluoroacetate in the presence of NaOMe in methanol under reflux. Subsequent diarylpyrazole formation from the condensation of dione 7 and 4-sulfonamidophenylhydrazine hydrochloride then delivered... 

Many continuous processes are used to prepare early pharmaceutical intermediates, but Pfizer recently presented a continuous process to prepare the API itself. A continuous process to prepare the anti-inflammatory drug celecoxib was described (Scheme 11.3) [6]. The batch process for celecoxib consists of two steps (1) a base-mediated Claisen reaction between 4-methylacetophenone and ethyl trifluoroacetate, and (2) an acid-mediated pyrazole condensation between enolate intermediate 8 and hydrazine 9 giving celecoxib (Scheme 11.4) [7]. Continuously flowing the Claisen reaction step 1 into the pyrazole condensation step 2 offers the advantages of directly telescoping continuous processing steps, as described in the introduction to this chapter. 

Synthesis The condensation of 4-methylacetophenone with ethyl acetate by means of NaOMe in refluxing methanol gives 4,4,4-trifluoro-1-(4-methylphenyl)butane-1,3-dione, which cyclized with 4-hydrazinophenyl-sulfonamide in refluxing ethanol (Graul et al., 1977 Talley et al. (Searle Co.), 1995. 

AcadAboensis, MathPhys 14, No 3, 9 pp( 1943) ChemZtr 1943 II, 1268-69 CA 38, 5492(1944) [By nitration of 3-chloro-p-cymene and repeated crystn from AcOH, there was obtd 2,4-Dinitro 3 chlorotoluene (qv), mp 90 90.5° this compd also resulted by reaction of 3-chlorotoluene with fuming HN03 St coned H2S04 and crystn from 85% AcOH. This compd is reported identical with the supposed 3,5 Dinitro 2 chloro 4 methylacetophenone or N. Ganguly R. LeFevre, CA 28, 5416(1934). Q M report that the latter compd other derivs of G LeF have not been prepd and should be removed from the chemical literature] 2,4,6-Trlnltro-3-chlorotoluene, (02N)3(C1).-C6H.CH3 mw 261.58, N 16.07% wh ndls (from benz + petr eth), mp 148.5-151° readily sol in AcOH, benz, acet or chlf less sol in ale, eth or petr eth was prepd by nitrating, with mixed acids, either 2,4-dinitro 5 chloro-toluene or 3 chlorotoluene(Refs 1 3) and by... 

Methylacetophenone, AP30 1-Methyl-2-acetylhydrazine, AGIO Methyl a 11oxan, AD90 Methylamine, AA31... 

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