Date of Graduation

1973

Document Type

Dissertation/Thesis

Abstract

The Chapman rearrangem ent o f dim ethyl N -cyanoim idocarbonate (89)» dim ethyl N -cyanothioim idocarbonate (90)» and N ,N -dim ethylN '-cyanom ethylisourea ( 91) has been In v e s tig a te d . N -C yanotrim ethylurea (2ft) 5 th e normal Chapman rearrangem ent product o f 91» was observed along w ith se v e ra l o th e r compounds when £1 was h eated n e a t f o r se v e ra l h o u rs. Among th e p ro d u cts o f th e rearrangem ent o f 91 were th re e isom eric o x ad iazin es. These compounds were probably formed by a 1 ,4 a d d itio n o f an N -acyl carb o d iim id e ( r e s u ltin g from a 1 ,4 0 —*»N m igration o f th e methyl group in 91) a c ro ss th e cyano group o f compound £1 . In c o n tra s t to 91» 89 and £0, upon b eing h e ate d , underwent q u a n tita tiv e conversion to th e corresponding carbam ate and th io - carbam ate, re s p e c tiv e ly . The k in e tic s o f th e Chapman rearrangem ent o f 82 and £0 in bromobenzene were follow ed by both nmr and i r spectroscopy w ith th e l a t t e r being th e b e t t e r method. Both 89 and £0 were found to obey f i r s t - o r d e r k in e tic s . The r a t e co n sta n ts ( i r method) f o r 8£ ranged from 3 .20* 0.10 x 10” ^ sec""* a t 100° to 3 6 t l . 3 x 10"^ sec""* a t 130° and th e E , AH*, and dS* were 2 4 ,2 1 0.5L d> k cal/m o l, 2 3 .5 * 0 .4 9 kcal/m o l, and - 1 7 * 2 .0 eu , re s p e c tiv e ly , fo r t h i s compound. The r a te co n sta n ts ( i r method) f o r compound £0 ranged from 4 . 8 * 0.22 x 10~5 sec ”1 a t 120° to 50i 5 .0 x 10-5 sec""* a t 150° w hile th e E ,

Download

Share

COinS