Nitrobenzoyl chlorides

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Nitrobenzoyl chlorides
Surname 2-nitrobenzoyl chloride 3-nitrobenzoyl chloride 4-nitrobenzoyl chloride
other names o -nitrobenzoyl chloride m -nitrobenzoyl chloride p -nitrobenzoyl chloride
Structural formula Structure of 2-nitrobenzoyl chloride Structure of 3-nitrobenzoyl chloride Structure of 4-nitrobenzoyl chloride
CAS number 610-14-0 121-90-4 122-04-3
PubChem 11875 8495 8502
Molecular formula C 7 H 4 ClNO 3
Molar mass 185.57 g mol −1
Physical state solid / liquid firmly
Brief description yellow needles or
orange liquid		 yellow crystalline solid
with a pungent odor		 yellow crystalline
powder
Melting point 17-20 ° C 31-35 ° C 73 ° C
boiling point 148–149 ° C (9  hPa ) (Decomp.) 155 ° C (20  hPa )
GHS
labeling
05 - Corrosive
danger
05 - Corrosive 07 - Warning
danger
05 - Corrosive
danger
H and P phrases 314 312-314 314
no EUH phrases no EUH phrases no EUH phrases
280-305 + 351 + 338-310 280-301 + 330 + 331
302 + 352-305 + 351 + 338-310 		280-301 + 330 + 331
305 + 351 + 338-310-402 + 404

In chemistry , the nitrobenzoyl chlorides form a group of substances that is derived from both benzoyl chloride and nitrobenzene . The structure consists of a benzene ring with attached –COCl group and nitro group  (–NO 2 ) as substituents . Their different arrangement ( ortho , meta or para ) results in three constitutional isomers with the empirical formula C 7 H 4 NO 3 Cl. The 4-nitrobenzoyl chloride is used in the analysis of organic substances.

presentation

The nitrobenzoyl chlorides are obtained from the nitrobenzoic acids by reaction with thionyl chloride (SOCl 2 ) or phosphorus trichloride (PCl 3 ).

Preparation of 4-nitrobenzoyl chloride from 4-nitrobenzoic acid by reaction with phosphorus trichloride (PCl3).

properties

The nitrobenzoyl chlorides are yellowish liquids or crystalline solids with a pungent odor. The 4-nitrobenzoyl chloride, which has the highest symmetry, has the highest melting point. 2-Nitrobenzoyl chloride is thermally unstable. When heated to temperatures above 110 ° C, e.g. B. in vacuum distillation, the compound can decompose explosively.

use

The 4-nitrobenzoyl chloride is mainly used in the analysis of organic substances by derivatization . It is used in cases when a substance in question is more sensitive and direct esterification with 4-nitrobenzoic acid in the presence of sulfuric acid is not possible. As a rule, the reaction takes place in pyridine in order to bind the released HCl immediately.

See also

Individual evidence

  1. ↑ a b Roth / Weller: Hazardous chemical reactions, ecomed security, Hüthig Jehle Rehm publishing group, Landsberg / Lech, 31st supplementary delivery 8/2000.
  2. ↑ a b c data sheet 2-nitrobenzoyl chloride from Sigma-Aldrich , accessed on May 14, 2017 ( PDF ).
  3. ↑ a b c Entry on 3-nitrobenzoyl chloride in the GESTIS substance database of the IFA , accessed on March 12, 2017(JavaScript required) .
  4. ↑ a b c Entry on 4-nitrobenzoyl chloride in the GESTIS substance database of the IFA , accessed on March 12, 2017(JavaScript required) .
  5. ^ Gattermann / Wieland : The practice of organic chemists , 43rd edition, Walter de Gruyter , Berlin · New York 1982, ISBN 3-11-006654-8 , p. 304: " p -Nitrobenzoylchlorid".
  6. ↑ a b Association of authors: Organikum , 19th edition, Johann Ambrosius Barth, Leipzig · Berlin · Heidelberg 1993, ISBN 3-335-00343-8 , p. 440.
  7. ^ Association of authors: Organikum , 19th edition, Johann Ambrosius Barth, Leipzig · Berlin · Heidelberg 1993, ISBN 3-335-00343-8 , p. 424.

Web links

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