Toluene → HCID 23463257, compound

Participants

Reaction Steps

A mixture of THPC (19.06 g, 0.1 mol), 1,3-dimethylurea (17.62 g, 0.2 mol), and toluene (150 ml) was heated to reflux in an apparatus fitted with a mechanical stirrer and a Dean-Stark trap for azeotropic removal of the water. The mixture was held at reflux unitl the evolution of water ceased (4 hr); this condensation, as might be expected, required a longer reflux period and more efficient stirring to displace the last of the water than that of Example 1. Half of the 7.2 ml (100.0%) of water was collected during the first 15 min. The product, which separated during the reaction as a mass of white solids, was broken up, triturated under acetonitrile to remove a resinous by-product (4.09 g), filtered, rinsed with acetonitrile and dried, giving 26.21 g (86.3%) of 3,9-dioxo-2,4,8,10-tetramethyl-2,4,8,10-tetraaza-6-phosphoniaspiro[5.5]undecane chloride (II, R=R'=CH3, X=Cl) as a white, crystalline solid. Two recrystallizations from 2-propanol (12 ml/g) gave pure product, mp 161°-162° C. and resolidifying, then mp 217° C. dec.

Provenance & Evidence