Certain Reactions of p-Bromocinnamic Acid

Abstract

Ethyl 7-Chlorobutyrate.-Thirty-five grams (77%) of this product was obtained when 40 g. of y-ethoxybutyric acid, which boiled at 114-116°(7 mm.),20 and 54 g. of thionyl chloride were heated on a steam-bath for four hours. The ethyl -chlorobutyrate boiled at 70-71°( 10 mm.).21 When 30 g. of the ester was heated for six hours on a steam-bath with 18 cc. of coned, hydrochloric acid and the mixture extracted with ether, 8 g. of y-chlorobutyric acid, b. p. 104-109°( 6 mm.), and 18 g. of unchanged ester were obtained. Upon further fractionation, 4 g. of the acid was found to boil at 107-108°( 6 mm.); m. p. 13°.22 The following compounds were prepared in the manner described above. Ethyl iodobutyrate was obtained in 67% yield; b. p. 69-71°( 3 mm.).23Ethyl y-diethylaminobutyrate was prepared in 78% yield; b. p. 73-75°( 4 mm.).24 The hydrochloride, after recrystallization from a mixture of acetone and ether, melted at 113°.

Diaryl Dihydropyrazole-3-carboxamides with Significant In Vivo Antiobesity Activity Related to CB1 Receptor Antagonism: Synthesis, Biological Evaluation, and Molecular Modeling in the Homology Model

“…The aldehydes 34 and 35 were procured from Sigma-Aldrich, and aldehydes 55 − 64 were synthesized as per literature procedure . Although there is sufficient literature evidence available for synthesis of α,β-unsaturated keto esters, the present set of conditions afforded compounds 38 , 39 , and 75 − 84 in better yields and are scalable. −

2

3

4

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“…20 Although there is sufficient literature evidence available for synthesis of R,β-unsaturated keto esters, the present set of conditions afforded compounds 38, 39, and 75-84 in better yields and are scalable. [21][22][23][24][25][26][27][28] As dihydropyrazole analogues 4-24 contained a chiral center at position 5, the above synthesis provides a target compound in the form of racemic mixture. To further explore the stereochemical (chiral) requirements/consequences for binding to the CB1 receptor, the key compound 9 was synthesized as a chiraly pure moiety by introducing resolution at suitable stage.…”

Practical Asymmetric Hydrogenation-Based Synthesis of a Class-Selective Histone Deacetylase Inhibitor

“…18 Dibromination of 4 using bromine in tetrachloromethane or organocatalysis have been reported. 19 We have run this reaction simply in DCM at room temperature and obtained the 2,3dibromoester 12 as a solid in 96% yield. In the subsequent steps, the double HBr elimination followed by the esterification The double HBr elimination reaction was quite challenging due to the formation of various impurities (Scheme 3).…”

“…After filtration, DCM was removed by vacuum distillation, and the crude product was recrystallized from ethyl acetate and heptane (v/v, 1/2). The product was collected by filtration, and the filter cake was dried in vacuum oven at 40 °C/ 25 (19). To a 1 L three-neck flask equipped with a mechanical stirrer, temperature probe, and nitrogen inlet, 18 (98%, 85.4 g, 0.300 mol), HOBt (40.5 g, 0.300 mol), and DMF (430 mL) were charged.…”

“…General analytical methods and copies of 1 H and 13 C NMR for compounds 1,5,6,7,9,10,11,13,14,16,17,18,19, and 29; synthesis of [Ru(OAc) 2 ((R)-furyl-MeOBIPHEP)] (29), crystallographic data (tables of bond lengths and angles, complete atomic coordinates, anisotropic displacement coefficients, and isotropic displacement coefficients for hydrogen atoms) and analytical data (HRMS, 1 H NMR, 31 P NMR, IR, and Raman). This material is available free of charge via the Internet at http://pubs.acs.org.…”