Boiling isopropanol

The formation of insoluble nitroso dimers is only observed in reactions involving fuctionalization at C-19 whereas 18-nitroso compounds apparently rearrange rapidly to the 18-oximes. However in most cases it is recommended that rearrangement be completed by brief treatment of the crude irradiation product in boiling isopropanol. 

Starting from 2.3 g (0.1 gatom) of sodium in 60cc ethanol,9.1 g (0.05 mol) of 3,5-diethoxy-phenol in 25 cc of ethanol, and 9.3 g (0.05 mol) of 1-chloro-2-morpholinoethane hydrochloride in 15 cc of ethanol, 12 g (yield 72.4%) of white crystals melting at 183°C to 184°C were obtained after recrystallization from 50 cc of boiling isopropanol, which were soluble in water, slightly soluble in ethanol, and insoluble in hydrocarbons. 

SYNTHESIS To a solution of 1.21 g 5-methoxyindole-3-carboxaldehyde in 15 mL nitroethane there was added 0.3 g anhydrous ammonium acetate, and the mixture was held at steam-bath temperature. Periodic assay by TLC showed the reaction to be complete in 1.5 h. The volatiles were removed under vacuum, and the residue (1.58 g of rusty red crystals) was recrystallized from 15 mL boiling isopropanol. After filtration and air-drying, there was obtained 1.24 g (82%) of 5-methoxy-3-(2-nitropropenyl)indole as dull gold crystals with a melting point of 178-179 °C. The literature value is 182-184 °C. 

In many cases, bridged polycyclic ketones react relatively slowly in the Meerwein-Ponndorf-Verley reduction and the thermodynamic equilibrium is obtained using aluminum isopropoxide in boiling isopropanol. The equilibrium depends on the substituents (see refs 5, 183 and 184). 

In a sequential three-component condensation, dimedone and 1,2-diaminobenzene were reacted in boiling isopropanol in the presence of acetic anhydride for 40 min. 

Samples of leaves of corresponding age, harvested from replicate sets of stressed and control plants, were weighed, extracted with boiling isopropanol, followed by chloroform methanol (2 1 then 1 2, v/v) and washed by the procedure of Folch et al. (1957) to separate the lipid fraction. Thin layer chromatography and estimations of lipids were carried out as described previously (L5sel and Lewis, 1974). In studies of incorporation of C-labelled photosynthate into lipids, 0.5 g samples of leaves were laid on damp filter paper in a transparent plastic box, allowed to photosynthesize in for 30 minutes and for... 

Obtained by condensation of a-chloro-3,4-dihydroxy-acetophenone with cyclopentylamine in ethanol or isopropanol at 60-80° [4795] or in boiling isopropanol for 30 min (98%) [4796]. 

Also obtained by reaction of epichlorohydrin with quinacetophenone in the presence of potassium hydroxide in boiling isopropanol for 48 h [5875], m.p. 127-129° [5875]. 

Chondrus crispus and Polysiphonia lanosa (still attached to its brown alga host, Ascophyllum nodosum), collected from along the South Wales coast, were stored and Incubated as described. Lipids were extracted by the boiling Isopropanol procedure . Initial fractionation was on acid-washed Florosil columns and further analysis was as before. ... 

Portions of kanamycin-rcsistant calli and plants were killed in boiling isopropanol and extracted with hcxane/isopropanol (3 2). Lipids were fractionated on BioSil A, and... 

To a well-stirred mixture of 100 gm (1.66 mole) of boiling isopropanol is added dropwise a solution of 164 gm (0.55 mole) of potassium dichromate and 120 ml of concentrated sulfuric acid in 1 liter of water. The addition takes 30 min and the aldehyde distills off as it is formed. The propionaldehyde is redistilled to yield 44-47 gm (45-49%), bp48°-55°C, rtgP 1.3636. 

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