Some Novel Schiff Bases from Pyruvic Acid with Amines Containing N &S Donor Atoms: Synthesis, Spectral Studies and X-Ray Crystal Structures

Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) Å, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.

孟加拉国扶贫模式:社会支出战略

高贫困率会极大地影响一个国家的经济社会发展。孟加拉国采取了诸多扶贫政策措施,取得了良好成效。孟加拉国贫困率从2005年的40.0%下降到了2020年的20.5%,短短15年内实现了贫困率减半。由于政府出台了扶贫专项措施,并重视社会支出,贫困人口的经济社会地位显著提升。成绩的取得主要归因于采取有针对性的措施、直接惠及贫困人口、包容性发展、基于宪法义务和理念、政策延续性及其渐进式推进,以及政府与非政府组织合作的强有力的制度框架。由于新冠疫情爆发,贫困加剧,孟加拉国应当延续上述政策。此外,长期性的解决方案能够激发贫困人口的潜能,鼓励他们参与生产活动,摆脱贫困。