Reaction of N-vinylindazolium tetrafluoroborates with aqueous potassium carbonate or sodium borohydride affords 2,3-dihydroquinazolines which evolve to 1,2,3,4-tetrahydroquinazolines by intra or intermolecular nucleophilic attack. The X-ray structure of one tetrahydroquinazoline, the tricyclic compound 17a, was determined (C14H16N2O5, P21/n, a=6.001(4)Å, b=13.601(8)Å, c=17.452(6)Å, β=94.93(3)°, V=1419(1)Å3
N-乙烯基吲哚四氟硼酸盐与碳酸钾水溶液或硼氢化钠反应,得到2,3-二氢喹唑啉,其通过分子内或分子间亲核攻击演变成1,2,3,4-四氢喹唑啉。确定了一种四氢喹唑啉三环化合物17a的X射线结构(C 14 H 16 N 2 O 5,P2 1 / n,a = 6.001(4)Å,b = 13.601(8)Å,c = 17.452 (6)A,β= 94.93(3)°,V = 1419(1)埃3,ž = 4,- [R对于1541个观察到的反射= 0.078)。当这些盐与甲醇反应时,仅获得开链化合物。2-乙烯基吲唑鎓和3-乙烯基苯并三唑四氟硼酸盐与碳酸钾水溶液和硼氢化钠反应,通过裂解唑-乙烯基键产生相应的中性苯并唑。它们将甲醇添加到环外双键上,在吲唑衍生物的情况下,在碱性介质中可观察到向1,2-二氢喹唑啉的扩展。提出了乙烯基吡唑鎓和吲唑鎓盐与亲核试剂反应的一般机理。
A new synthesis of the GPIIb/IIIa receptor antagonist SB-214857-A
作者:Ian P Andrews、Richard J Atkins、Neil F Badham、Richard K Bellingham、Gary F Breen、John S Carey、Stephen K Etridge、Jerome F Hayes、Nigel Hussain、David O Morgan、Andrew C Share、Stephen A.C Smith、Timothy C Walsgrove、Andrew S Wells
DOI:10.1016/s0040-4039(01)00843-7
日期:2001.7
A new synthesis of lotrafiban SB-214857-A is reported. The key steps are the preparation of racemic (4-melhyl-3-oxo-2,3,4,5-tetrahydro-1H-benzo[c][1,4]diazepin-2-yl)-acid methyl ester from 2-nitrobenzyl alcohol, a resolution using an immobilised lipase enzyme and a palladium-catalysed aminocarbonylation reaction. (C) 2001 Elsevier Science Ltd. All rights reserved.