Halogeno-ethers

Nitroamlines. Acetyl derivatives (p. 388), Benzoyl derivatives (p. 388). Diamines. Diacet> l derivatives (p. 388), Dibenzoyl derivatives (p. 388). Halogeno-hydrocarbons, a-Naphthyl ethers (from reactive halogen compounds, p. 391, and their Picratcs, p. 394), Nitro-derivatives (p.39i). Carboxylic acid (if oxidisable side chain) (p. 393). 

Almost insoluble in cold water. Higher alcohols (including benzyl alcohol), higher phenols (e.g., naphthols), metaformaldehyde, paraldehyde, aromatic aldehydes, higher ketones (including acetophenone), aromatic acids, most esters, ethers, oxamide and domatic amides, sulphonamides, aromatic imides, aromatic nitriles, aromatic acid anhydrides, aromatic acid chlorides, sulphonyl chlorides, starch, aromatic amines, anilides, tyrosine, cystine, nitrocompounds, uric acid, halogeno-hydrocarbons, hydrocarbons. 

Ring expansion of haloalkyloxiranes provides a simple two-step procedure for the preparation of azetidin-3-ols (Section 5.09.2.3.2(f)) which can be extended to include 3-substituted ethers and O-esters (79CRV331 p. 341). The availability of 3-hydroxyazetidines provides access to a variety of 3-substituted azetidines, including halogeno, amino and alkylthio derivatives, by further substitution reactions (Section 5.09.2.2.4). Photolysis of phenylacylamines has also found application in the formation of azetidin-3-ols (33). Not surprisingly, few 2-0-substituted azetidines are known. The 2-methoxyazetidine (57) has been produced by an internal displacement, where the internal amide ion is generated by nucleophilic addition to an imine. 

In this connection it should be mentioned that dihalogenomethyl methyl ethers did not furnish the expected / -disuIfone nor the a-halogeno sulfones as preliminary steps in appreciable amounts surprisingly, sulfonyl halides have been isolated as main products of these conversions208 ... 

Photoaddhion of electron donor olefins such as vinyl ethers and stilbene to variously methyl and halogeno-substituted 1,4-benzoquinones resulted in the formation of dihydrobenzofurans via a dienone-phenol rearrangement of the primary product spirooxetanes <96H(43)619>. High-temperature water seems to be an alternative to use of acid catalysts or organic solvents by the cyclization of allyl phenyl ethers to dihydrobenzofurans <96JOC7355>. 

The replacement of the reactive 5-chloro by a sulfonamido group in 1,2,4-thiadiazoles affords a convenient synthesis of the 5-sulfonamido heterocycles.92- 3,168-172 173 Thus, 5-halogeno compounds (171), on treatment with p-acetamidobenzenesulfonamide and potassium carbonate in diphenyl ether at 200°, afford the sulfonamido derivatives (170) in 70 % yields. Nitrobenzenesulfonamides do not react. This route is valuable, because the products are obtainable with difficulty by sulfonylation of the parent amine (see Section III,D, 1,A).8-8S-86-87 The superiority of route 171 -> 170 over route 169-y 170, though unusual in the heterocyclic field, recalls similar observations made in the synthesis of sulfonamidotriazines.174... 

Acyl and sulphonyl halides, a-halogeno-ethers and alkyl iodides react rapidly. 

These ethers have been made by primary synthesis (see Section 29.1) or by alcoholysis of halogeno-2,6-naphthyridines (see Section 29.3.2). 

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