N-mono or N,N-di:substd. urea cpds. prodn. in high yield - comprises reacting ammonium isocyanate with prim. or sec. amine in diluent, without needing to isolate free isocyanic acid

Prodn. of N-mono- or N,N-di-substd. urea (I) is carried out by reacting NH4NCO with a prim. or sec. amine (I) in a diluent (III). (III) is inert under the reaction conditions and pref. is an aliphatic or aromatic (chloro)hydrocarbon, ether, alcohol or water. Alternatively, (II) also acts as (III). NH4NCO and (II) are used in equiv. amts., unless (II) also acts as (III). Either (a) (II) is added to a stirred mixt. of NH4NCO and (III) or (b) NH4NCO is stirred into (II) and opt. (III) at temps. from -20 deg. C and room temp. and reaction is completed by (a) heating to the reflux temp. of (III) or (b) increasing the reaction temp. (I) is isolated from the reaction mixt. in the usual way. ADVANTAGE - NH4NCO can be used directly, without isolating the free acid. The process is simple and gives good yields. In an example, a soln of 28.1g (0.15 mole) dodecylamine in CHCl3 was added to a suspension of 10.8g NH4NCO (83%; 0.15 mole) in 90 ml CHCl3 at room temp. The mixt. was stirred for 1 hr, then heated 2 hr. under reflux. After cooling, the ppte. was filtered and dried, giving 33.5g dodecylurea (98% of the theory), m.pt. 102-105 deg. Cs ad