A PHP Error was encountered

Severity: Warning

Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests

Filename: helpers/my_audit_helper.php

Line Number: 176

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 1034
Function: getPubMedXML

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3152
Function: GetPubMedArticleOutput_2016

File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
Line: 316
Function: require_once

Synthesis of pyrazine-phosphonates and -phosphine oxides from 2H-azirines or oximes. | LitMetric

Synthesis of pyrazine-phosphonates and -phosphine oxides from 2H-azirines or oximes.

Org Lett

Facultad de Farmacia, Universidad del País Vasco, Apartado 450, 01080 Vitoria, Spain.

Published: July 2002

[reaction: see text] Tetrasubstituted pyrazines containing two phosphonate groups 2 in positions 2 and 5 and trisubstituted pyrazines containing a phosphonate 5 or a phosphine oxide group 7 in position 2 are obtained by thermal treatment of 2H-azirine-2-phosphonates 1 and -phosphine oxides 6. These pyrazines can also be prepared from beta-ketoxime tosylates 9 and 10 or from oxime derived from phosphine oxide 11.

Download full-text PDF

Source
http://dx.doi.org/10.1021/ol0261534DOI Listing

Publication Analysis

Top Keywords

-phosphine oxides
8
pyrazines phosphonate
8
phosphine oxide
8
synthesis pyrazine-phosphonates
4
pyrazine-phosphonates -phosphine
4
oxides 2h-azirines
4
2h-azirines oximes
4
oximes [reaction
4
[reaction text]
4
text] tetrasubstituted
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!