{"id":704,"date":"2015-02-15T06:10:26","date_gmt":"2015-02-15T06:10:26","guid":{"rendered":"http:\/\/biomedpharmajournal.org\/?p=704"},"modified":"2020-04-25T07:35:35","modified_gmt":"2020-04-25T07:35:35","slug":"greener-synthesis-of-pharmacologically-important-thiosemicarbazides","status":"publish","type":"post","link":"https:\/\/biomedpharmajournal.org\/staging\/vol2no1\/greener-synthesis-of-pharmacologically-important-thiosemicarbazides\/","title":{"rendered":"Greener Synthesis of Pharmacologically Important Thiosemicarbazides"},"content":{"rendered":"

Introduction<\/strong><\/p>\n

The synthesis of thiosemicarbazides has been the area of extensive research since decades especially while investigating compounds to be potential pharmacological candidates. Thiosemicarbazides have shown unique spectrum of anticonvulsant1<\/sup>, antifungal2<\/sup>, plant growth promoting3<\/sup>, antibacterial4<\/sup>, anti-tubercular5<\/sup> properties. Microwave Assisted Organic Synthesis (MAOS) serve as one of the greener methodologies in organic synthesis. It has become increasingly important in performing chemical transformations in minutes instead of hours by conventional methods.<\/p>\n

Under the framework of \u201cMAOS\u201d we propose to present a very simple, fast and ecofriendly procedure where the reaction of substituted isothiocyanate with substituted acid hydrazides leads for the\u00a0\u00a0 synthesis of some thiosemicarbazides. The synthesized compounds were evaluated for anti bacterial activity against S. aureus and E. coli.<\/p>\n

Experimental<\/strong><\/p>\n

Melting points were determined in open capillary tubes and are uncorrected. The purities of the compounds were checked on silica-gel-coated Al plates (Merck). 1<\/sup>H-NMR spectra was measured on Advance Bruker DRX-300 using solution in hexadeuterio dimethyl sulfoxide (DMSO) with trimethyl silane(TMS) as the internal standard , chemical shifts are given in\u00a0 \u03b4 (ppm) and protons signals are indicated as :s= singlet, d = doublet, t = triplet, m = multiplet. Elemental analysis was performed on Elementor Vario EL III at C.D.R.I., Lucknow.<\/p>\n

IR spectra were recorded in KBr on a Perkin Elmer Spectrum RX-1 FT-IR spectrophotometer. Microwave irradiations were carried out in an IFB domestic microwave oven. All chemicals were of analytical grade.<\/p>\n

General procedure<\/strong><\/p>\n

Method A(Heating). <\/em>Substituted malonamic acid hydrazide(5mmol) and stirred solution of substituted phenyl isothiocyanates (5mmol) in\u00a0 ethanol (10 mL) was refluxed for 3 hrs, and then filtered to give the corresponding thiosemicarbazide which was recrystallized from ethanol6<\/sup>.<\/p>\n

Method B(Microwave irradiation).<\/em> Substituted malonamic acid hydrazide(5mmol), ethanol (5-8 drops) and substituted phenyl isothiocyanate (5mmol) were irradiated in microwave for 2-6 mins. Solid obtained was purified by recrystallization from hot ethanol.<\/p>\n\n\n\n
\"Scheme<\/td>\n\n

Scheme 1:<\/strong><\/p>\n

Click here to View Scheme<\/a><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

R = 2-CH3<\/sub> and 4-CH3<\/sub><\/p>\n

R1 <\/sub>= H, 4-Br, 4- OC2<\/sub>H5 <\/sub>and 4- CH3<\/sub><\/p>\n

Table 1: Thiosemicarbazides obtained by the condensation of N-(2-methyl) phenyl malonamic acid hydrazide with different phenyl isothiocyanates.<\/strong><\/p>\n\n\n\n
S. No<\/strong><\/td>\n\u00a0\u00a0\u00a0\u00a0\u00a0 R1 <\/sub><\/strong><\/td>\nMol. Formula<\/strong><\/td>\nM.P<\/strong><\/p>\n

(o<\/sup>C)<\/strong><\/td>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 % Yi<\/p>\n","protected":false},"excerpt":{"rendered":"

Introduction The synthesis of thiosemicarbazides has been the area of […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-704","post","type-post","status-publish","format-standard","hentry","category-vol2no1"],"_links":{"self":[{"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/posts\/704","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/comments?post=704"}],"version-history":[{"count":6,"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/posts\/704\/revisions"}],"predecessor-version":[{"id":32994,"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/posts\/704\/revisions\/32994"}],"wp:attachment":[{"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/media?parent=704"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/categories?post=704"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/biomedpharmajournal.org\/staging\/wp-json\/wp\/v2\/tags?post=704"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}