Trimethyl orthoacetate → Methyl 2-methyl-6-nitrobenzoate

HRID 1964070Notes

Reaction equation

HRID 1964070 reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]([N+:11]([O-:13])=[O:12])[C:3]=1[C:4]([OH:6])=[O:5].[C:14](OC)(OC)(OC)C>>[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]([N+:11]([O-:13])=[O:12])[C:3]=1[C:4]([O:6][CH3:14])=[O:5]

Participants

3

Reactant 2

HCID 15050Trimethyl orthoacetateHCID 160976-Methyl-2-nitrobenzoic acid

Product 1

HCID 596057Methyl 2-methyl-6-nitrobenzoate

Conditions

Temperature
22.5 °C

Procedure

A mixture of 2-methyl-6-nitrobenzoic acid (300.0 g, 1.66 moles, from Acros Organics, Morris Plains, N.J.) and trimethyl orthoacetate (298.3 g, 2.48 moles, from Aldrich Chemicals, Milwauke, Wis.) was charged into a 3-L 3-necked flask at about 20-25° C. under nitrogen. The reaction mixture was gradually heated and the low-boiling point components generated during the reaction were distilled off to an internal temperature of 95-100° C. After 2 hours, the reaction mixture was cooled to 20-25° C. over 1-2 hours. After heptane (1.50 L, from Aldrich Chemicals) was charged into the reaction mixture over 1.0-1.5 hours, the reaction mixture was seeded with methyl 2-methyl-6-nitrobenzoate (0.5 g) when it became turbid. The suspension was cooled to 0-5° C. over 0.5-1 hour and kept at 0-5° C. for another 1.5-2 hours. The solid was collected by filtration under vacuum, washed with heptane (3x300 mL), and dried to a constant weight in a tray at 30-35° C. under a vacuum at 100-120 torr. The yield of methyl 2-methyl-6-nitrobenzoate was 292.0 g (91%), based on 300.0 g of 2-methyl-6-nitrobenzoic acid. The product was found to have a purity of >99% measured by HPLC based on area percentage, and a water content of <0.1% measured by Karl Fisher titration.

Workup

  1. additionwas charged into a 3-L 3-necked flask at about 20-25° C. under nitrogen
  2. temperatureThe reaction mixture was gradually heated
  3. distillationwere distilled off to an internal temperature of 95-100° C
  4. additionAfter heptane (1.50 L, from Aldrich Chemicals) was charged into the reaction mixture over 1.0-1.5 hours
  5. temperatureThe suspension was cooled to 0-5° C. over 0.5-1 hour
  6. waitkept at 0-5° C. for another 1.5-2 hours
  7. filtrationThe solid was collected by filtration under vacuum
  8. washwashed with heptane (3x300 mL)
  9. customdried to a constant weight in a tray at 30-35° C. under a vacuum at 100-120 torr

Sources & evidence

ORD record
ord-9be91eeb4a044f16a52858b48885340c
Source dataset
uspto-grants-2013_04
Patent number
US08415485B2

Reaction notes

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