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70 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

VIa VIb

Holleman points out that such good agreement between the calculated and

experimental values is not always the case. Moreover, instances are known of de

viations from the substitution rules. According to Holleman [55] they may be as-

cribed in many instances to insufficient accuracy in the experimental data.

Marked deviations were observed when the nitro group was introduced into

benzene derivatives with three substituents, e.g. into 2,3-dichloroacetanilide (Holle-

man and Hollander [52]).

Earlier Lobry de Bruyn [68] found that the nitration of o- and m- chloroacetani-

lides (VII) and (X) gave the products VIII, IX and XI, respectively:

(30)

VII VIII 59% IX 39%

(31)

X XI 56%

From this Holleman inferred that in the nitration of dichloroacetanilide (XII)

the nitro group should enter the 6- position, yet he obtained the substitution almost

exclusively in 4- position (XIII)

XII XIII

Vorozhtsov [21] referred to the nitration of m- nitroacetanilide (XIV) as an

example of inconsistency between the results obtained and predicted, viz.: