error CS0246: The type or namespace name ‘Newtonsoft’ could not be found (are you missing a using directive or an assembly reference?)

I’m trying to dockerize a .net api project which runs on .netframework version 4.7.2. I can run the application locally with no issues , but when i try to dockerize the same source code I’m getting the above error

The docker build fails at msbuild command

Docker file:

# start with a base image with all the necessary tooling to compile our app
FROM mcr.microsoft.com/dotnet/framework/sdk:4.8 AS build

# set the working directory inside compilation container to c:\app
WORKDIR /app
COPY . .

# setting up RSA key
WORKDIR C:/Windows/Microsoft.NET/Framework64/v4.0.30319
RUN aspnet_regiis -pi CoreconKeys "/app/keys.xml"
WORKDIR /app
ARG npm_token 
ENV npm=${npm_token}

# restore nuget packages
RUN nuget restore

# use msbuild to publish project to c:\publish
RUN msbuild .\Corecon_API.sln /p:DeployOnBuild=true /property:Configuration=Release /p:PublishProfile=FolderProfile /p:PublishUrl="c:\publish"

FROM mcr.microsoft.com/windows/servercore/iis
RUN powershell Install-WindowsFeature NET-Framework-45-ASPNET ; \  
Install-WindowsFeature Web-Asp-Net45 ; Install-WindowsFeature Web-Windows-Aut

WORKDIR /inetpub/wwwroot
# copy files from bin/publish in our sdk container into c:\inetpub\wwwroot
COPY --from=build /publish. ./

Error message:
click here

"C:\app\Corecon API.sin" (default target) (1) ->
"C:\app\CoreconlebApi2\CoreconWebApi2.csproj" (default target) (20) ->
"C:\app\CoreconwebApi.Integration.Stratosphere\CoreconwebApi.Integration.Stratosphere.csproj"(defaulttarget)(22:2) ->
(CoreCompile target) ->
  C:\app\CoreconWebApi.Integration.Stratosphere\Parser.cs(2,7): error C50246: The type or namespace name "Newtonsoft" could not be found (are you missing a using directive or an assembly reference?) [C:\app\CoreconWlebApi.Integration.Stratosphere\CoreconWebApi.Integration.Stratosphere.csproj]
  C:\app\CoreconWebApi.Integration.Stratosphere\StratoService.cs(10,7):error CS0246: The tvpe or namespace name "Newtonsoft" could not be found (are vou missing a using directive or an assembly reference?) C:\app\CoreconwebApi.Integration.Stratosphere\CoreconWebApi.Integration.Stratosphere.csproj

    200 Warning(s)
    2 Error(s)

I can find all the packaged got restored inside container under the packages folder after nuget restore

I’m expecting to build a docker image out of this!!