Water-acetone

Finally, in the last step, the chelating auxiliary had to be removed Ideally, one would like to convert 4.54 into ketone 4.55 via a retro Mannich reaction. Unfortunately, repeated attempts to accomplish this failed. These attempts included refluxing in aqueous ethanol under acidic and basic conditions and refluxing in a 1 1 acetone - water mixture in the presence of excess paraformaldehyde under acidic conditions, in order to trap any liberated diamine. Tliese procedures were repeated under neutral conditions in the presence of copper(II)nitrate, but without success. 

Thus in neutral medium the reactivity of 2-aminothiazoles derivatives toward sp C electrophilic centers usually occurs through the ring nitrogen. A notable exception is provided by the reaction between 2-amino-thiazole and a solution (acetone-water, 1 1) of ethylene oxide (183) that yields 2-(2-hydroxyethylamino)thiazole (39) (Scheme 28), Structure 39... 

Isoprene [78-79-5] (2-methyl-1,3-butadiene) is a colorless, volatile Hquid that is soluble in most hydrocarbons but is practically insoluble in water. Isoprene forms binary azeotropes with water, methanol, methylamine, acetonitrile, methyl formate, bromoethane, ethyl alcohol, methyl sulfide, acetone, propylene oxide, ethyl formate, isopropyl nitrate, methyla1 (dimethoxymethane), ethyl ether, and / -pentane. Ternary azeotropes form with water—acetone, water—acetonitrile, and methyl formate—ethyl bromide (8). Typical properties of isoprene are Hsted in Table 1. 

A Hquid-phase isophorone process is depicted ia Figure 4 (83). A mixture of acetone, water, and potassium hydroxide (0.1%) are fed to a pressure column which operates at head conditions of 205°C and 3.5 MPa (- 500 psi). Acetone condensation reactions occur on the upper trays, high boiling products move down the column, and unreacted acetone is distilled overhead ia a water—acetone a2eotrope which is recycled to the column as reflux. In the lower section of the column, water and alkaH promote hydrolysis of reaction by-products to produce both isophorone and recyclable acetone. Acetone conversion is typically ia the range 6—10% and about 70% yield of isophorone is obtained. Condensation—hydrolysis technology (195—198), and other Hquid-phase production processes have been reported (199—205). 

Fig. 41. The pervaporation separation of acetone—water mixtures achieved with a water-selective poly(vinyl alcohol) (PVA) membrane and with an acetone-selective siUcone mbber membrane. The PVA membrane is best suited to removing small amounts of water from a concentrated acetone solution, whereas the siUcone mbber membrane is best suited to removing small amounts of acetone from a dilute acetone stream (89).

Entering gas Acetone Water vapor Sensible heat... 

Sorenson and Arlt Liquid-Liquid Equilihiium Data Collection, DECHEMA, Frankfurt, Germany, 1979) report several sets of liquid-liquid equilibrium data for the system acetone-water-chloroform, but the lowest solute concentrations reported at 25 C were. 3 weight percent acetone in the water layer in equilibrium with 9 weight percent acetone in the chloroform layer. This gives a partition ratio K of, 3.0. 

Meldrum s acid (3) To malonic acid 1 (52 g, 0 5 mol) in acetic anhydride (60 mL, 0 6 mol) was added cone HjSOa while stimng Acetone 2 (40 mL, 0 55 moO was added Cooling lor 24 h, filtration, washing the solid with ice water and recrystallization from acetone-water gave 3 (35 g, 49%), mp 94-95 C (dec)... 

Dimetbyl-l,3-propanediol (neopentyl glycol) [126-30-7] M 104.2, m 128.4-129.4°, b 208°/760mm. Crystd from benzene or acetone/water (1 1). 

Geraniol [106-24-1] M 154.3, b 230 , d 0.879, n 1.4766. Purified by ascending chromatography or by thin layer chromatography on plates of kieselguhr G with acetone/water/liquid paraffin (130 70 1) as solvent system. Hexane/ethyl acetate (1 4) is also suitable. Also purified by GLC on a silicone-treated column of Carbowax 20M (10%) on Chromosorb W (60-80 mesh). [Porter Pure Appl Chem 20 499 7969.] Stored in full, tightly sealed containers in the cool, protected from light. 

Propionamide [79-05-0] M 73,1, m 79.8-80.8 , pK -0.9 (Ho scale, aq H2SO4). Crystd from acetone, benzene, CHCI3, water or acetone/water, then dried in a vacuum desiccator over P2O5 or cone H2SO4. 

Sudan IV [Solvent Red 24, l-(4-o-tolylazo-o-tolylazo)-2-naphthol] [85-83-6] M 380.5, m -184 (dec), Cl 26105, Xmax 520nm, pK jt -9.0. Crystd from EtOH/water or acetone/water. 

Tetramethylammonium bromide [64-20-0] M 154.1, sublimes with dec >230°. Crystd from EtOH, EtOH/diethyl ether, MeOH/acetone, water or from acetone/MeOH (4 1) by adding an equal volume of acetone. It was dried at 110° under reduced pressure or at 140° for 24h. 

The general reaction procedure and apparatus used are exactly as described in Procedure 2. Ammonia (465 ml) is distilled into a 2-liter reaction flask and to this is added 165mlofisopropylalcoholandasolutionof30g(0.195 mole) of 17/ -estradiol 3-methyl ether (mp 118.5-120°) in 180 ml of tetrahydrofuran. The steroid is only partially soluble in the mixture. A 5 g portion of sodium (26 g, 1.13 g-atoms total) is added to the stirred mixture and the solid dissolves in the light blue solution within several min. As additional metal is added, the mixture becomes dark blue and a solid (matted needles) separates. Stirring is inefficient for a few minutes until the mass of crystals breaks down. All of the sodium is consumed after 1 hr and 120 ml of methanol is then added to the mixture with care. The product is isolated as in Procedure 4h 2. After being air-dried, the solid weighs 32.5 g (ca. 100% for a monohydrate). A sample of the material is dried for analysis and analyzed as described in Procedure 2 enol ether, 91% unreduced aromatics, 0.3%. The crude product may be crystallized from acetone-water or preferably from hexane. 

B-Norcholesterol Acetate (71). A test tube containing 2 g (4.4 mmoles) of (70) is placed in an oil bath at 150° and the temperature of the bath is slowly raised. At 170°, the liquified mass begins to froth and after 15 min the evolution of CO2 is essentially complete. The melt is allowed to stand at 180° for an additional 15 min. After cooling to room temperature and trituration with 5 ml of acetone, long white plates separate. The crystals are removed by filtration and washed with 70% acetone-water to yield 1.74 g (94%) of (71) mp 77-79°. 

Zr(03PCH3), 2(03PC6H4S03H)o8, acetone, water, reflux 30 min-24 h, 70-95% yield. Semicarbazones, tosylhydrazones, and hydrazones are also cleaved."... 

A mixture consisting of 22.7 g potassium o-bromobenzoate, 16.6 g 2,6-dichloro-3-methvlani-line, 12 ml N-ethylmorpholine, 60 ml diethylene glycol dimethyl ether, and 1.0 g anhydrous cupric bromide is heated in a nitrogen atmosphere at 145 C to 155°C for 2 hours. The reaction mixture is diluted with 60 ml diethylene glycol dimethyl ether and acidified with 25 ml concentrated hydrochloric acid. The acidic mixture is diluted with 100 ml of water and the liquid phase decanted from the insoluble oil. The insoluble oil is stirred with methanol and the crystalline N-(2,6-dichloro-3-methylphenyl)anthranilic acid which separates is collected and washed with methanol. The product, after recrystallization from acetone-water mixture melts at 248 C to 250°C. 

---