Novel reaction of N,N'-bisarylmethanediamines with formaldehyde. Synthesis of some new 1,3,5-triaryl-1,3,5-hexahydrotriazines.
The acid-catalyzed cyclocondensation of N,N'-bisaryl (aryl = 2-pyrimidinyl, 2-pyrazinyl and 4-nitrophenyl) methanediamines 5a-c with aqueous formaldehyde in refluxing acetonitrile leads to the formation of the corresponding 1,3,5-triaryl-1,3,5-hexa-hydrotriazines 6a-c. The stoichiometric reactions of 2-aminopyrimidine and 2-amino-pyrazine with aqueous formaldehyde in acetonitrile under reflux conditions also afforded 6a and 6b, respectively. Treatment of 2-aminopyrimidine with aqueous formaldehyde in a 3:2 ratio yielded N,N',N"-tris(2-pyrimidinyl)dimethylenetriamine (7a) as a sole product, which upon subsequent reaction with formaldehyde also afforded 6a. The reaction of N,N'-biphenylmethanediamine with formaldehyde was also investigated.
Revisitation of formaldehyde‐aniline condensation. III. The Cyclic Tetramer of N‐Methyleneaniline: An X‐ray diffraction structure determination
The cyclic tetramer of N-methyleneaniline, one of the products from the condensation between formaldehyde and aniline under neutral condition, has been characterized as 1.3.5.7-tetraphenyltetrazocine (3) and its crystal structure elucidated by X-ray diffraction.
A simplified synthesis of (±)-1,2-diphenyl-1,2-diaminoethane (1) from benzaldehyde and ammonia. Revision of the structures of the long-known intermediates “hydrobenzamide” and “amarine”
Abstract A new pathway for the simple, stereocontrolled and economical synthesis of (±)- 1 from benzaldehyde is described. The structures of two intermediates (Scheme 1) have been revised to those shown in Scheme 2.