Acetyl chloride Alcohols, preparation

Acetophenone. Acetophenone [98-86-2] (methyl phenyl ketone) is a colorless Hquid that forms laminar crystals at low temperature (mp 20°C). It has a characteristic sweet orange blossom odor, and is soluble in alcohols and ethers. It is found in nature in oil of casatoreum, obtained from beavers oil of labdanum, recovered from plants and in buds of balsam poplar. It can be prepared by the Friedel-Crafts reaction (qv) of acetyl chloride with benzene in the presence of aluminum chloride however, this route is of Htde commercial significance. 

Imidates 60 were prepared in two steps by first reacting nitrile derivatives with various alcohols. The condensation of the obtained iminoester with appropriate acetyl chloride resulted in the formation of the title compounds 60a-c (Scheme 12). The structures of the products 60 were elucidated by means of spectroscopic analysis. 

The 4,5-dihydro-3,2-benzothiazepine (380) has been prepared by the thermally induced ring expansion of 1-azidoisothiochroman (74LA734). The product reacted with acetyl chloride and then with alcohols to give the l-alkoxy-2-acyl derivatives, and was oxidized to the 3,3-dioxide. 

Several attempts to prepare typical alcohol derivatives of [Cr(HO-A)2]-were unsuccessful these include Schotten-Bauman conditions (acetyl chloride in chloroform shaken with cold, aqueous alkaline solution of complex), refluxing in acetyl chloride, in glacial acetic acid, acetyl chloride in hot dimethyl formamide, acetyl chloride and pyridine in acetonitrile, and acetic anhydride in acetonitrile. The failure of refluxing acetyl chloride to effect acetylation brings to mind the work of Keller and Edwards (4) the acetyl chloride system is completely heterogeneous and consequently not conducive to reaction. However, even the homogeneous reaction of [Cr(HO-A)2] — with acetyl chloride in acetonitrile failed to give a measurable quantity of the diester. 

Polystyrene-bound allylic or benzylic alcohols react smoothly with hydrogen chloride or hydrogen bromide to yield the corresponding halides. The more stable the intermediate carbocation, the more easily the solvolysis will proceed. Alternatively, thionyl chloride can be used to convert benzyl alcohols into chlorides [7,25,26]. A milder alternative for preparing bromides or iodides, which is also suitable for non-benzylic alcohols, is the treatment of alcohols with phosphines and halogens or the preformed adducts thereof (Table 6.2, Experimental Procedure 6.1 [27-31]). Benzhy-dryl and trityl alcohols bound to cross-linked or non-cross-linked polystyrene are particularly prone to solvolysis, and can be converted into the corresponding chlorides by treatment with acetyl chloride in toluene or similar solvents (Table 6.2 [32-35]). 

The preparation of various alkenylbenzo[6]thiophenes by dehydration of side-chain alcohols is discussed in Section VI, J. l,l-Di(2-benzo[6]thienyl)ethylene may be prepared by treating 2-benzo[6]-thienyllithium with acetyl chloride,132 and the olefins (158a-d) may... 

Reaction of 2-benzo[6]thienyllithium (and its 7-methyl derivative 90) with aldehydes 486,5fl4, 620 or ketones 467 483 affords a secondary or tertiary alcohol, respectively. Treatment of 2-benzo[6]thienyl-lithium with acetyl chloride gives mainly l,l-di(2-benzo[6]thienyl)-ethylene.132 Side-chain alcohols in positions other than the 2-position are most easily prepared by reaction of the appropriate benzo[6]-thienylmagnesium halide with aldehydes 460,471 or ketones,186,3o9, 349, 4 7,466,479,498 or foy reaction of a benzo[fe]thiophene aldehyde, ketone, or ester with an alkylmagnesium halide.358,427 465 The preparation of alcohols from 2- and 3-benzo[6]thienylmethyl-magnesium chloride485,528 is discussed in Section VI, D, 4. 

Acetic formic anhydride has been prepared by the reaction of formic acid with acetic anhydride2 3 and ketene,4,5 and of acetyl chloride with sodium formate.6 The present procedure is essentially that of Muramatsu.6 It is simpler than others previously described and gives better yields. It is easily adapted to the preparation of large quantities, usually with an increase in yield. Acetic formic anhydride is a useful intermediate for the formyl-ation of amines,3,7 amino acids,8,9 and alcohols,2,10 for the synthesis of aldehydes from Grignard reagents,11 and for the preparation of formyl fluoride.12... 

Anhydrobisdibenzylsilicanediol is formed when 2 mols. of dibenzylsilicanediol condense with loss of 1 mol of water. Though the yield is not good, the best method of preparation is as follows Dibenzylsilicanediol (3 grams) is dissolved in 20 c.c. of dry ether, acetyl chloride (30 drops) added, and the solution in a beaker is kept in a desiccator over potassium hydroxide for three hours. It is then connected to the pump and evacuated to remove most of the acid chloride. After six hours, crystals of termolecular silicone usually appear on the surface. The solution is then poured into excess of cooled, dilute ammonium hydroxide and shaken. After extraction with ether and evaporation, the oily residue is treated with a little alcohol, which precipitates the silicone. The filtered alcoholic solution is diluted with water, and vigorous rubbing of the beaker with a glass-rod causes... 

It will be remembered that, in these reactions, the previously prepared chloride was not used, but that hydrochloric acid was conducted into a mixture of the acid and alcohol (see acetyl chloride), or the add was heated with alcoholic hydrochloric add (see B. 28, 3252). 

Alkylated starch can be fragmented by acetolysis into water soluble tri- and tetra-saccharides.742 Formic acid, together with a small amount of acetyl chloride, may be used instead.743 Alkyl a-D-glucosides can be prepared by treating starch with hydrogen chloride a solution of hydrochloride in a simple alcohol.744... 

Dispersive power is more constitutive than refractivity—a fact first recognized by Gladstone (1886, 1887) when investigating the quotients (w — nXl) d and M nXl — nX2)jd for additivity. Briihl (1891), using the Lorentz-Lorenz expression for the specific or molecular refractions, considerably extended the subject and prepared lists of atomic dispersions for the a and y hydrogen lines these were later revised by von Auwers and Eisenlohr. Tables such as those produced by the last-named author (1912, 1923) have always included values for Rp — Ra and Ry — Ra. Predicted dispersions are sometimes satisfactory when absorption wavelengths are well away from the visible region (e.g. from Table 2 Ry — Ra for acetyl chloride and pentyl alcohol are 0-44 and 0-64 cm3 the observed differences are 0 48 and 0-64 cm3 2 ... 

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