Hypochlorite, f-butyl

There are two sequences in which the reaction can be carried out. For most anilines the first step is /V-chlorination which can be done with t-butyl hypochlorite[9]. However, for anilines with ER substituents it may be preferable to halogenate the thioester. The halogenation can be done with Cl2[lbl or SOjCljCU]. For some anilines simply adding f-butyl hypochlorite to a mixture of the aniline and thioester is satisfactory (Entries 1, 4, Table 7.6). 

Treatment of a carborane derivative of thiirane with A-bromosuccinimide gives a j3-bromodisulfide (79MI50601). Chlorination of CM-2,3-di-f-butylthiirane by f-butyl hypochlorite proceeded differently to the reaction with chlorine itself (Scheme 41) (74JA3146). 

Another reagent which effects chlorination by a radical mechanism is f-butyl hypochlorite. The hydrogen-abstracting species in the chain mechanism is the f-butoxy radical. 

The reaction of sulphides 59 bearing an ethynyl or a carbomethoxy group a to sulphur with f-butyl hypochlorite in methanol or ethanol gives high yields of the corresponding a-alkoxy sulphides (60) rather than sulphoxides (equation 29). Oxidation of benzo[b]thiophene with t-butyl hypochlorite in t-butyl alcohol at 30-40° gave the corresponding 2-chloro-l-benzothiophen-l-oxide 61 in 45% yield (equation 30). 

It has been reported1 that, during the preparation of f-butyl hypochlorite according to the directions published in this series,2 an explosion occurred and caused moderate physical damage and minor injury to the operator. The cause of the accident has been attributed to lack of proper temperature control during addition of chlorine. It is strongly recommended that the reaction vessel be fitted with a thermometer that dips into the reaction mixture and that the rate of flow of chlorine be regulated so that the temperature of the reaction mixture never exceeds 20°. 

Chlorinated poly(styrene) samples were prepared by chlorination of PS with CI2 in trifluoroacetic acid(9) or by free radical chlorination using f-butyl hypochlorite(lO) or by chloromethylation using chloromethyl actyl ether and SnCU(ll). 

An example of electrophilic substitution on position C2 of the fused furan has been reported for 8H-furo[3,4-d]dibenz[ 7,/]azepine, which reacts with f-butyl hypochlorite to afford a mono chlorinated furan ring product (1995H431). 

The orf/to-formylation of 2-aminopyridines can be effected via the rearrangement of the azasulfonium salt prepared from a 2-aminopyridine, 1,3-dithiane, f-butyl hypochlorite and sodium methoxide (74CC685). The crude sulfilimine (815) was refluxed in f-butanol containing potassium f-butoxide to yield the dithioacetal (816). Hydrolysis of (816) with mercury(II) oxide/boron trifluoride etherate gave the aldehyde (817 Scheme 191). This method should be applicable to the formylation of other heterocyclic amines. 

Pyridazine-3,6-diones (diazaquinones) are prepared from cyclic hydrazides by oxidation with lead tetraacetate or other oxidizing agents, such as f-butyl hypochlorite, chlorine or nickel peroxide. 

In a similar manner to the formation of pyridazines from N- aminopyrroles, cinnolines or phthalazines are obtainable from the corresponding 1-aminooxindoles or 2-amino-phthalimides. If the relatively inaccessible 1-aminooxindoles are treated with lead tetraacetate, mercuric acetate, f-butyl hypochlorite (69JCS(C)772) or other agents, cinnolones are formed as shown in Scheme 105. The reaction was postulated to proceed via an intermediate... 

The A-chloro compound 176, obtained from the corresponding meth-oxyamide with f-butyl hypochlorite, was cyclized to l-methoxy-2-indolone 163 by silver carbonate in trifluoroacetic acid (87% yield) (84JA5728), or by other silver or mercury salts (87T2577), and more conveniently by anhydrous zinc acetate in 1,2-dichloroethane (91% yield) (87CL1771). The reaction proceeds through the spiro intermediate 177, followed by both possible 1,2-shifts. 

---