Reference

Preparation of carbodiimides and polycarbodiimides by the decarboxylation of isocyanates in the presence of organophosphorus compounds

Preparation of carbodiimides and polycarbodiimides by the decarboxylation of isocyanates in the presence of organophosphorus compounds. Mysin, N. I.; Fridland, S. V.; Yurkova, N. N.; Dergunov, Yu. I. (USSR). Khim. Prom-st. (Moscow), (7), 398-401 (Russian) 1984. CODEN: KPRMAW. ISSN: 0023-110X. DOCUMENT TYPE: Journal CA Section: 39 (Synthetic Elastomers and Natural Rubber) Several organophosphorus compds.Several reagents such as 37401-90-4 is used here. are prepd. and used as catalysts in decarboxylation of isocyanates or polymn. of diisocyanates to give carbodiimides and polycarbodiimides, resp. The latter are evaluated as hydrolytic stabilizers of urethane rubber. The highest conversion of isocyanates (e.g., 83.8% for 3,4-dichlorophenyl isocyanate [102-36-3]) was achieved with 3-methyl-1-phenyl-3-phospholene oxide (I) [7564-51-4]. Polymn. of diisocyanates in the presence of I was carried out by 3 different schemes, varying reaction conditions to obtain polymers with desired properties. Thus, 2,4-TDI was polymd. 7 h at 25° in the suspension of I in 2,4-TDI, to give an org. solvent-sol. polymer having m.p. 85°, NCO group content 6.65%, and mol. wt. 786. This polymer, when added to the urethane rubber ESKU-50, increased the tensile strength of rubber after hydrolytic aging for 24 h from 140 to 270 kg/cm2. .

Method for preparing N,N-dimethyl-N'-phenylureas by the reaction of dimcarb with optionally substituted phenyl isocyanates

Method for preparing N,N-dimethyl-N'-phenylureas by the reaction of dimcarb with optionally substituted phenyl isocyanates. (Ucb, S.A., Belg.). PCT Int. Appl. WO 9706134 A1 20 Feb 1997, 16 pp. DESIGNATED STATES: RW: AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE. (French). (World Intellectual Property Organization).Several reagents with their cas registry numbers 150-68-5 and 102-36-3 are used here. CODEN: PIXXD2. CLASS: ICM: C07C273-18. APPLICATION: WO 1996-BE81 1 Aug 1996. PRIORITY: GB 1995-16444 4 Aug 1995. DOCUMENT TYPE: Patent CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds) Section cross-reference(s): 45 N,N-dimethyl-N'-phenylureas, having optional substituents on the 3 and/or 4 position(s) of the Ph ring, are prepd. in high yield by the reaction of the corresponding (un)substituted Ph isocyanate with an excess amt. of boiling dimcarb. The high-purity product is recovered simply by distg. off the dimcarb, which may then be recycled, without further processing, to another isocyanate reaction step. Thus, dimcarb (prepd. by the reaction of Me2NH with CO2) was reacted with 4-chlorophenyl isocyanate, producing Monuron (m.p. 174.2°) in 98.75% yield (based on HNMe2). .