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bear2007

铁杆木虫 (著名写手)

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求 美国化学文摘
CA    124卷    编号  289555   和  260371  的信息,谢谢!
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周文娟

木虫 (小有名气)

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bear2007(金币+12,VIP+0):十分感谢文娟的帮忙,提醒你一下,把木虫的名字改一下,不要用真名。 12-16 17:23
Search Strategy
(CAN)(124:289555)

Copyright (c) 1997 American Chemical Society   All Rights Reserved.

124:289555
Preparation of cyclic carbonates.
Dotani, Masaharu; Kanbara, Yutaka; Ookawa, Takashi (Mitsubishi Gas
Chemical Co, Japan).  Jpn. Kokai Tokkyo Koho JP 07330756 A2 19
Dec 1995 Heisei, 4 pp. (Japan).  CODEN: JKXXAF.  CLASS: ICM:
C07D319-06.  ICS: B01J023-02; B01J023-06; B01J023-14;
B01J027-232.  ICA: C07B061-00.  APPLICATION: JP 94-126269 8
Jun 1994.  DOCUMENT TYPE: Patent CA Section: 28 (Heterocyclic
Compounds (More Than One Hetero Atom))
The title compds. are prepd. by reaction of R1CH(OH)CR2R3CH(OH)R4
[R1 - R4 = H, alkyl] with urea under reduced pressure, in the presence of
a catalyst.  Thus, a mixt. of urea 60.1 g (1 mol), 1,3-propanediol 95.1 g
(1.25 mol), and zinc carbonate 6 g under reduced pressure (80 mmHg)
was heated for 5 h at 175?to give 92.1 g 1,3-dioxan-2-one.

Keywords

cyclic carbonate prepn
alkanediol carbonylation
urea reaction alkanediol

Index Entries

Carbonylation
carbonylation of alkanediol by urea
546-93-0
1314-13-2, uses
3486-35-9
2453-03-4
3592-12-9
17361-58-9
57-13-6, reactions
107-88-0
126-30-7
504-63-2
prepn. of cyclic carbonates
Search Strategy
(CAN)(124:260371)

Copyright (c) 1997 American Chemical Society   All Rights Reserved.

124:260371
Catalytic preparation of dialkyl carbonates from alkanediols and urea.
Dotani, Masaharu; Kanbara, Yutaka; Ookawa, Takashi (Mitsubishi Gas
Chemical Co, Japan).  Jpn. Kokai Tokkyo Koho JP 07330686 A2 19
Dec 1995 Heisei, 6 pp. (Japan).  CODEN: JKXXAF.  CLASS: ICM:
C07C069-96.  ICS: B01J031-04; C07C068-00; C07C068-06.  ICA:
C07B061-00.  APPLICATION: JP 94-126271 8 Jun 1994.
DOCUMENT TYPE: Patent CA Section: 23 (Aliphatic Compounds)
Dialkyl carbonates, useful as solvents, processing agents for synthetic
fibers, materials for polymers, drugs, etc., are prepd. by (1) treatment of
HOCHR1CR2R3CHR4OH (I; R1-4 = H, C1-4 alkyl) with urea and (2)
treatment of the resulting 6-membered carbonates with alcs. under
recycling of I obtained from step (2) to step (1).  A mixt. of urea,
1,3-butanediol, Zn acetate was heated under stirring at 155?and 50
mm Hg for 5 h and the reaction mixt. contg. 4-methyl-1,3-dioxan-2-one
(II, yield 88.8% at urea conversion 100%) was further treated with
MeOH at 120?for 3 h to give Me2CO3 and Me 3-hydroxybutyl carbonate
with selectivity 73.4 and 25.1%, resp., at II conversion 49.0%.

Keywords

alkyl carbonate prepn
alkanediol cyclocondensation urea transesterification alc
propylene carbonate transesterification alc
carbonic acid dialkyl ester prepn

Index Entries

Cyclocondensation reaction catalysts
Zn, Mg or Pb; prepn. of dialkyl carbonates from urea and alcs. while
recycling alkanediols
Transesterification catalysts
Alcohols, reactions
prepn. of dialkyl carbonates from urea and alcs. while recycling
alkanediols
62502-19-6
162461-37-2
162461-38-3
175220-03-8
107-88-0
126-30-7
504-63-2
546-93-0
557-34-6
1184-55-0
3486-35-9
2453-03-4
3592-12-9
17361-58-9
105-58-8
463-79-6, dialkyl esters
616-38-6
623-96-1
57-13-6, reactions
71-23-8, reactions
prepn. of dialkyl carbonates from urea and alcs. while recycling
alkanediols
2楼2009-12-16 17:09:42
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