Reference

N-Carbobenzoxy-L-aspartic anhydride

N-Carbobenzoxy-L-aspartic anhydride. (Ajinomoto Co., Inc., Japan). Jpn. Kokai Tokkyo Koho JP 58167578 A2 3 Oct 1983 Showa, 3 pp. (Japanese).Some commonly used reagents like 1152-61-0 and 88966-25-0 are used in this experiment. (Japan). CODEN: JKXXAF. CLASS: IC: C07D307-66. APPLICATION: JP 82-51629 30 Mar 1982. DOCUMENT TYPE: Patent CA Section: 34 (Amino Acids, Peptides, and Proteins) The title compd. (I) was prepd. by dehydrating the acid (II) with Ac2O in the presence of acids having dissocn. consts. >5 ′ 10-2. Thus, 0.15 g 98% H2SO4 and 33.7 g Ac2O were added to 80.2 g II in PhMe at 55° to give, after 3 h, 89% I. .

Preparation of 2-cyanopiperazine and (S)-N-tert-butyl-2-piperazinecarboxamide

Preparation of 2-cyanopiperazine and (S)-N-tert-butyl-2-piperazinecarboxamide. Takuma, Yuki; Kasuga, Yuzo; Miyazaki, Takeki; Mizuho, Yuji; Okamoto, Ken; Murakami, Takeshi (Mitsubishi Chemical Corporation, Japan).Several substances are used for example 1152-61-0 and 187589-38-4 which are their cas registry numbers. Eur. Pat. Appl. EP 754686 A1 22 Jan 1997, 15 pp. DESIGNATED STATES: R: CH, DE, FR, GB, IT, LI. (English). (European Patent Organization). CODEN: EPXXDW. CLASS: ICM: C07D241-04. APPLICATION: EP 1996-401619 19 Jul 1996. PRIORITY: JP 1995-182857 19 Jul 1995; JP 1995-264059 12 Oct 1995; JP 1995-264060 12 Oct 1995. DOCUMENT TYPE: Patent CA Section: 28 (Heterocyclic Compounds (More Than One Hetero Atom)) 2-Cyanopiperazine (I) was prepd. by cyclocondensation of, e.g., a 2-haloacrylonitrile with H2NCH2CH2NH2. Title carboxamide, an intermediate for prepn. of the HIV protease inhibitor indinavir, was prepd. by treating I with Me3COH in the presence of an acid followed by optical resoln. .