Detail of "2603-10-3"

Reference

Aromatic polycarbamates and polyisocyanates

Aromatic polycarbamates and polyisocyanates. Ryu, Ji Yong; Brownstein, Arthur M. (Exxon Research and Engineering Co. , USA). Ger. Offen. DE 3205072 A1 18 Aug 1983, 35 pp. (German). (Germany). CODEN: GWXXBX. CLASS: IC: C07C125-065; C07C125-073; C07C120-14; C07C118-00. APPLICATION: DE 82-3205072 12 Feb 1982. DOCUMENT TYPE: Patent CA Section: 35 (Chemistry of Synthetic High Polymers) Section cross-reference(s): 25 An arom. nitrile is prepd. by ammoxidn. of an alkylarom. compd., converted in turn to an arom. amide and an arom. carbamate, and condensed with a carbonyl compd. such as an aldehyde to give a compd. which contains >1 carbamate group and decomps. to give a compd. contg. >1 isocyanate group. The method is useful for the prepn. of polyisocyanates such as (4-OCNC6H4)2CH2 (I) [101-68-8]. Thus, PhCN [100-47-0] was prepd. by the ammoxidn. of toluene [108-88-3], converted in turn to benzamide [55-21-0] and PhNHCO2Me [2603-10-3], and condensed with HCHO [50-00-0] to prep. [4-(MeO2CNH)C6H4]2CH2 [7450-63-7], which was thermally decompd. in 35% conversion to I.

Aromatic carbamates and isocyanates

Aromatic carbamates and isocyanates. Ryu, Ji Yong; Brownstein, Arthur M. (Exxon Research and Engineering Co. , USA). U.S. US 4415745 A 15 Nov 1983, 10 pp. Cont.-in-part of U.S. Ser. No. 290,005. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C07C125-06; C07C118-00. NCL: 560025000. APPLICATION: US 82-343583 28 Jan 1982. PRIORITY: US 80-179062 18 Aug 1980; US 81-290005 4 Aug 1981. DOCUMENT TYPE: Patent CA Section: 35 (Chemistry of Synthetic High Polymers) An arom. polyisocyanate is prepd. comprising sequentially the following steps: ammoxidn. of a methylated arom. compd. such as PhMe [108-88-3]; hydrolysis of the arom. nitrile; conversion of the resultant amide to a carbamate; condensation with HCHO; and decompn. of the condensation product. Thus, a :4:1 M mixt. of H2O-O2-NH3-PhMe was passed over 5 mL Cr2O3-vanadia-Al2O3 catalyst to obtain PhCN [100-47-0]. As mixt. of 44.85 g PhCN and 0.76 g MnO2 was heated to 120°. H2O was added slowly and the mixt. was heated at 115-130° for 7 h to obtain benzamide (I) [55-21-0]. Me3COCl [507-40-4] (82 mmol) was added over 1 h to a reactor contg. a mixt. of I 75, MeONa [124-41-4] 80, and PhCl 12 mmol, and 4 mL MeOH. The mixt. was kept at 20° for 1 h then at 50° for 1 h to obtain 59.40 mmol Me N-phenylcarbamate (II) [2603-10-3]. A 53.7 g 37% HCHO soln. was added to 150 g II in 400 mL H2O at 93° then 100 mL HCl was added. The mixt. was heated at 93° for 24 h to obtain di-Me 4,4'-methylenebis(N-phenylcarbamate) (III) [7450-63-7]. A soln. of 11.0% III in C6H6 was thermally cracked to MDI [101-68-8] at 250°.