Nitration of p-cymene. Exchange and rearomatization reactions of p-cymene adducts

Abstract

Nitration of p-cymene in acetic anhydride gives a mixture of cis- and trans-1-isopropyl-4-methyl-4-nitro-1,4-dihydrophenyl acetate as the main product as well as 2- and 3-nitro-p-cymene and p-nitrotoluene. Acid-catalysed methanolysis of the acetoxynitro adduct gives a mixture of the cis- and trans-methoxynitro adducts. Under basic conditions the acetate adduct is converted into the corresponding alcohol which is in turn rearomatized to 2-isopropyl-4-methylphenol. The adducts rearomatize to 2-nitro-p-cymene in strong acid.

Ipso nitration. XX. Nitration of 5-tert-butyl-1,2,3-trimethylbenzene in acetic anhydride. Formation and rearomatization of adducts

“…6-tert-butyl-2,3,4-trimethylphenol, and to rearranged phenol, i.e. 2-tert-butyl-3,4,5-trimethylphenol, have been observed in other systems (3,12), and may apply here. Loss of the tert-butyl group also occurred in the solvolysis of the 1,4 adducts of y-tert-butyltoluene and 4-tert-butyl-o-xylene, although in the latter case this was a minor reaction, the major reaction being the normal 1,2 acetate shift leading to the aryl acetate.…”

Condemned to rootlessness: The loyalist origins of Canada's identity crisis

“…In New England, American historians were openly nostalgic, celebrating the virtues of Jeffersonian Yeoman Republicanism and comparing ancient Anglo-Saxon society with that of rural New England. 68 In the same manner, English-Canadian historians in the 1880s, many of Loyalist descent, coupled the nation's development 20 firmly to its Loyalist past. They described the Loyalists as the cream of colonial America and actively tried to weave images of old English aristocracy into their own nostalgic personal narratives.…”

“…Anglo-conformity, meanwhile, had colonial origins and spurred the expansion of the American ethnic core, absorbing non-English groups like the Huguenots, Welsh and a considerable number of Dutch and Germans. 20 As Richard Burkey put it, 'although pockets of European ethnicity still remained, by 1820 the great majority of the citizens of the new country were subscribing to a new ethnicity -American; only the racial groups were excluded from membership.' 21 Considering that the Puritans had arrived in Massachusetts in the 1620s, the gestation period for the American ethnie was roughly two hundred years, similar to our conservative estimate of Canadien ethnogenesis.…”

Nitration of p-tert-butyltoluene in acetic anhydride. 1,2 and 1,4 adducts

“…The present study is a continuation of our investigations of the formation and rearomatization reactions of adducts of 4-alkyltoluenes. Previous papers have dealt with y-xylene (5),p-cymene (6), and, in a preliminary communication, p-terlbutyltoluene (7). A distinguishing feature of this series is that the adducts are tertiary acetates.…”

“…The position il~so to the fert-butyl group is too hindered for attack of the nitronium ion to be competitive with attack at the other nuclear positions (15). i n contrast p-cymene does undergo attack ipso to the isopropyl group, both on reaction with nitric acid in acetic anhydride (6,16) and with nitronium tetrafluoroborate in tetramethylene s~llfone (15), and p-nitrotoluene is formed. N o side-chain (benzylic) products were obtained.…”