Ethyl-2-bromo-2-methyl propionate

Thus, the polymerisation of methyl methaciylate in toluene was investigated using an initial eatalyst/initiator/monomer molar ratio of 1 2 800 with ethyl 2-bromo-2-methyl-propionate as the initiator. Under these experimental eonditions, all the criteria of living polymerisation were fulfilled. Indeed, the plot of hi([M o/[Af]t) versus time followed a linear relationship, which is typical for a controlled polymerisation. Furthermore, a linear evolution... 

Figure 1. Experimental data for the polymerisation ofMMA initiated by ethyl 2-bromo-2-methyl-propionate and catalysed by complexes 4 ( ), 6 ( ), and 7 ( ).

The activity of complexes 8 and 9 was then investigated for the ATRP of MMA using the standard experimental conditions (85 °C, with ethyl 2-bromo-2-methyl-propionate as the initiator). With both mthenium-vinylidene complexes, the molecular weights increased hnearly with conversion. Furthermore, the semilogarithmic plot of xi( M f M d versus time also followed a linear relationship. These results strongly suggest that the polymerisation took place in a controlled fashion. However, an induction period was clearly evidenced in the plots of conversion versus time and versus... 

In a more detailed study, the same esterase P. fluorescens) was again subjected to mutagenesis using the same mutator strain, but also by saturation mutagenesis at selected positions 133a). In addition to 3-phenylbutyric acid ethyl ester (27), 3-bromo-2-methyl-propionic acid methyl ester rac-31) was chosen for the hydrolytic kinetic resolution, with the WT PFE showing an E factor of 12 in favor of the (5)-32. 

Sodium 2-Bromo-2-methyl-propionic acid ethyl ester... 

RX. n-butyl bromide n-dodecanyl iodide cyclohexyl iodide ethyl bromo acetate methyl 2,3-di-O-acetyl-4-O-benzoyl-6-bromo-6-deoxy-ot-D-glucopyranoside methyl 2,3,4-tri-0-acetyl-6-deoxy-6-iodo-0 -D glucopyranoside l,2 3,4-di-0-isopropylidene-6-deoxy-6-iodo-a-D-galactopyranose methyl 2(R)-[(tert-butoxycarbonyl)amino]-3-iodo-propionate cyclic bis(trifluoromethyl)oxazolidinone bromide. 

Miktoarm stars of the AB2C2 type, where A is PS, B is PfBA, and C is PMMA, were prepared with the trifunctional initiator 2-phenyl-2-[(2,2,6,6-tetramethyl)-l-piperidinyloxy] ethyl 2,2-bis [methyl(2-bromo propionato)] propionate (Scheme 76). A combination of NMRP and ATRP pol)Tnerization techniques... 

The reaction of potassium 3-amino-4-oxo-3,4-dihydroquinazoline-2-thiolate 62 with a-bromophenylacetic acid 63 resulted in the formation of (3-amino-4-oxo-3,4-dihydroquinazolin-2-ylsulfanyl)-phenyl-acetic acid methyl ester 64 which on alkali treatment and subsequent acidification resulted in the synthesis of 2-phenyl- 1-thia-4,4a,9-triaza-anthracene-3,10-dione 65 <1999JCR(S)86>. Similarly, the reaction of potassium 3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- pyrimidine-2-thiolate 66 with a-bromo-ester 67 resulted in the formation of 2-(3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- / pyrimidin-2-ylsulfanyl)-propionic acid ethyl ester 68. Subsequent treatment with alkali followed by acidification resulted in the formation of 2,3,7-trimethyl-3a,9a-dihydro-l,8-dithia-4a,5,9-triazacyclopenta[ ]naphthalene-4,6-dione 69 <2000JHC1161>... 

Automated parallel experiments were carried out to rapidly screen and optimize the reaction conditions for ATRP of methyl methacrylate (MMA) [34]. A set of 108 different reactions was designed for this purpose. Different initiators and different metal salts have been used, namely ethyl-2-bromo-tTo-butyrate (EBIB), methyl bromo propionate (MBP), (1-bromo ethyl) benzene (BEB), and p-toluene sulfonyl chloride (TsCl), and CuBr, CuCl, CuSCN, FeBr2, and FeCl2, respectively. 2,2 -Bipyridine and its derivatives were used as ligands. The overall reaction scheme and the structure of the used reagents are shown in Scheme 2. 

A solution of 4-[2-(5-ethyl-2-pyridyl)ethoxy]nitrobenzene (60.0 g) in methanol (500 ml) was hydrogenated at room temperature under one atmospheric pressure in the presence of 10% Pd-C (50% wet, 6.0 g). The catalyst was removed by filtration and the filtrate was concentrated under reduced pressure. The residual oil was dissolved in acetone (500 ml)-methanol (200 ml). To the solution was added a 47% HBr aqueous solution (152 g). The mixture was cooled, to which was added dropwise a solution of NaN02 (17.3 g) in water (30 ml) at a temperature not higher than 5°C. The whole mixture was stirred at 5°C for 20 min, then methyl acrylate (112 g) was added thereto and the temperature was raised to 38°C. Cuprous oxide (2.0 g) was added to the mixture in small portions with vigorous stirring. The reaction mixture was stirred until nitrogen gas evolution ceased, and was concentrated under reduced pressure. The concentrate was made alkaline with concentrated aqueous ammonia, and extracted with ethyl acetate. The ethyl acetate layer was washed with water and dried (MgS04) The solvent was evaporated off to leave methyl 2-bromo-3- 4-[2-(5-ethyl-2-pyridyl)ethoxy]phenyl propionate as a crude oil (74.09 g, 85.7%). 

A mixture of the crude oil of methyl 2-bromo-3- 4-[2-(5-ethyl-2-pyridyl)ethoxy]phenyl propionate (73.0 g) thiourea (14.2 g), sodium acetate (15.3 g) and ethanol (500 ml) was stirred for 3 hours under reflux. The reaction mixture was concentrated under reduced pressure, and the concentrate was neutralized with a saturated aqueous solution of sodium hydrogencarbonate, to which were added water (200 ml) and ether (100 ml). The whole mixture was stirred for 10 min to yield 5- 4-[2-(5-ethyl-2-pyridyl)ethoxy]benzyl -2-imino-4-thiazolidinone as crystals (0.3 g, 523.0%). Recrystallization from methanol gave colorless prisms, melting point 187°-188°C, dec. 

Testosterone. A 4-Chloro 17-acetate (S-114), 4-bromo (S-8), 4-methyl (S-11), 4-chloro 11/3-hydroxy 17-acetate (S-7), 4-fluoro 17-acetate (S-9), 4-hydroxy 17-acetate (S-10), la-methyl 4-chloro 17-acetate (S-79), 4-chloro 17-propionate (S-6), 4-hydroxy 17a-methyl (S-16), 4-chloro Ha-methyl (S-17), 4-mercapto 17a-methyl (S-49), 4-methylthio 17a-methyl (S-50), 4-ethylthio 17a-methyl (S-51), 4-acetylthio 17a-methyl (S-52), and 4-chloro 11/3-hydroxy 17a-methyl (S-102) substitutions all decrease the androgenic property. However, the anabolic potency is only slightly decreased and in a few cases increased, such as S-114, S-11, S-16, S-6. Substitution at the 4-position by bulky substituents i.e., 4-ethyl (S-13) and 4-allyl (S-14), abolishes both activities. 

C6H10Br2O2 ethyl 3-bromo-2-(bromomethyl)propionate 58539-11-0 495.65 43.466 2 7800 C6H10O methyl l-methylcyclopropyl ketone 1567-75-5 399.60 34.328 1,2... 

Ethyl propionate Isobutyl formate Isopropyl acetate Methyl butyrate Methyl isobutyrate Propyl acetate l-Bromo-3-methylbutane... 

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