2214-72-4Relevant articles and documents
Substituted 2-methylene-1,3-oxazolidines, -1,3-thiazolidines, -1,3-benzothiazines, -1,3-oxazines, and substituted imidazopyrimidinediones from Cl(CH2)nNCO and Cl(CH2)nNCS and active methylene compounds
Basheer, Ahmad,Rappoport, Zvi
, p. 9743 - 9750 (2006)
The reaction of ω-chloroalkyl isocyanates Cl(CH2) nNCO (n = 2 (2), 3 (4)) and isothiocyanate Cl(CH2) 2-NCS (3) with active methylene compounds CH2YY′ 1 in the presence of Et3N or Na give 2-YY′-methylene-1,3- oxazolidines, (E,Z)-1,3-thiazolidines, and 1,3-oxazines from 2, 3, and 4, respectively. 2-(Chloromethyl)-phenyl isocyanate 8 gives with 1 the corresponding benzo-oxazines. Ethyl 2-isothiocyanatobenzoate 10 gives the corresponding benzothiazolinone, whereas the analogous isocyanate 12 gives noncyclic enols. Ethoxycarbonyl isothiocyanate 14 gives an open-chain thioenol or an enol-thioamide. The cyanoamides CH2(CN)CONHR, R = H, Me, CHPh2, give with Et3N and 2 the bicyclic imidazopyrimidinediones 16, derived from two molecules of 2, but with their preformed Na salt they give the 1,3-oxazolidines. Reaction of cyanoacetamide with 3 in the presence of Na gave a tricyclic triaza(thia)indacene, derived from two molecules of 3. A reaction mechanism involving an initial attack of the anion 1- on the N=C=X (X = O, S) moiety gives an anion 18, which cyclizes intramolecularly and after tautomerization gives the mono-ring heterocycle. With the cyanoamides, the N- site of the ambident ion 18 attacks another molecule of 2 giving the anion 20, which by intramolecular attack on the CN, followed by expulsion of the Cl- gives the bicyclic 16 after tautomerization.
Tomalia,D.A. et al.
, p. 1400 - 1405 (1969)
SAFE AND EFFICIENT PROCESS FOR THE PREPARATION OF CARMUSTINE
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Paragraph 0092-0097, (2017/09/25)
Carmustine may be safely and efficiently produced by reacting 2-chloroethylamine hydrochloride and 1,1′-carbonyldiimidazole to afford 1,3-bis(2-chloroethyl)-1-urea, followed by nitrosation to give the final product.
PROCESS FOR PREPARATION OF CARMUSTINE
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Page/Page column 8, (2017/11/10)
The present invention relates to an improved process for preparation of carmustine (I). The present invention also relates to preparation of 1,3-bis(2-chloroethyl)urea (II) an intermediate used in preparation of carmustine.